Cohabitation and Romantic Relationship Quality Among Portuguese Lesbian, Gay, and Heterosexual Individuals

Lesbian and gay (LG) individuals are perceived as having poorer relationship functioning than heterosexual individuals, but this negative appraisal is not translated into actual relationship experiences. Indeed, relationship quality outcomes do not vary according to sexual orientation. Cohabitation status may play an important role, because it symbolizes relationship commitment and intimacy particularly for LG individuals. A cross-sectional study (N = 425, 52.9% women; Mage = 28.38, SD = 6.89) with romantically involved LG (38.4%) and heterosexual (61.6%) individuals examined the association between cohabitation and relationship quality outcomes. To isolate the role of cohabitation, cohabiting individuals were compared according to relationship legal status. Results showed that cohabiting (vs. non-cohabiting) LG individuals were more committed, invested, and satisfied, but those who legalized (vs. did not legalize) their union were only more committed. Among heterosexual individuals, no differences were observed. Furthermore, LG (vs. heterosexual) individuals were overall more committed, satisfied, and invested when cohabiting with their partner (especially in legalized unions), whereas heterosexual (vs. LG) individuals were more committed in non-cohabiting relationships. No other differences were found. This suggests that cohabitation may be used by LG individuals as a strategy to strengthen relationship quality and that legal recognition further increases relationship commitment.

Still, it is yet to be determined whether the presumed benefits of cohabitation among LG individuals are similar in countries in which same-sex marriage is already recognized, such as Portugal. Indeed, it could be argued that the legal recognition of same-sex unions is not per se the central issue in this discussion, but the fact that it legitimizes the Bexistence^of cohabitation in same-sex relationships. In the present article, we aim to examine to what extent relationship quality outcomes differ between LG individuals who are not cohabiting with their partner, those who are cohabiting without a legally recognized union, and those cohabiting with a legally recognized union. We also included heterosexual individuals in similar relationship conditions to define a baseline for comparisons.

Same-Sex Relationships and Cohabitation in Portugal
Research on same-sex relationships is typically conducted in the USA, where same-sex unions were legally recognized in some jurisdictions before being recognized nationwide in 2015. In contrast, our study was conducted in Portugal, where same-sex unions were legalized almost 17 years ago. Unregistered cohabitation legal rights (i.e., de facto unions) were first legally recognized for different-sex relationships in 1999 (Law n. 135/1999, August 28th) and extended to samesex relationships 2 years later. Same-sex marriage was only recognized much later, in 2010.
Briefly, de facto same-sex relationships were approved by the Portuguese parliament in 2001 (Laws n. 6/2001 andn. 7/ 2001, May 11th;Brandão & Machado, 2012). These bills set a common ground for a series of legislative changes proposed and approved afterwards, changing the panorama of LG rights in Portugal: the same-sex civil marriage law approved in 2010, the gender identity provision in 2011, and the adoption and joint adoption by same-sex couples law in 2016 (Oliveira, Costa, & Nogueira, 2013;Pereira & Monteiro, 2017). According to the Portuguese jurisdiction, de facto unions and marriages are similar in terms of legal benefits (e.g., taxes, access to healthcare; Pereira & Monteiro, 2017), despite some differences (e.g., de facto unions are not recognized as a civil state; they do not recognize a legal division of property acquired by the couple and do not include legal principles for heritage and heritance rights).
Portugal is a relevant context in which to study samesex relationships for two main reasons. First, there was an obvious growth in the number of same-sex unions in the last few years following its approval by the parliament (INE, 2017). Between 2010 and 2016, there were 2299 same-sex marriages registered at Civil Registry Offices. Second, and more importantly, there was a growing political and social visibility, as well as greater acceptance of same-sex relationships and of the LG community overall.
For instance, Poeschl, Silva, and Cardoso (2015) asked 240 Portuguese participants (with no reference to their sexual orientation) to associate five words to same-sex and to different-sex marriage. Results showed that Bloveŵ as a frequently evoked word for same-sex marriage. Comparing both types of marriages, words such as Bunion^and Brespect^were more frequently evoked for same-sex (vs. different-sex) marriage. Furthermore, samesex marriage was more frequently associated with gaining economic benefits, when compared to gaining a particular social status, or constitute a family. In a different line of research, Rodrigues, Fasoli, Huic, and Lopes (2017) showed that heterosexual participants did not evaluate differently a same-sex or a different-sex relationship, as long as both partners were described as being committed to their relationship and sexually monogamous.
Despite the importance of outlining the opinions, attitudes, and social representations of same-sex relationships, the majority of findings in Portugal do not directly inquire participants about their own relationship experiences. Extant evidence in Western countries that legally recognize same-sex unions suggests that these legal changes had a positive impact on relationship quality and psychological health. For instance, LG individuals in these countries report greater satisfaction in their relationship, more flexible and egalitarian divisions in household chores, greater openness to disclose sexual orientation, and more positive and closer relationships with families of origin and with families in-law (e.g., Clarke et al., 2010;Nico & Rodrigues, 2013;Rothblum, Balsam, Todosijevic, & Solomon, 2006). Yet, this type of studies in the Portuguese context is very scarce. An exception is the study by Pereira and Monteiro (2017)

that included online interviews to 425
LG individuals about the perceived impact on their lives following the political and legislative changes for same-sex unions in Portugal. A content analysis revealed two major themes: (1) possibility to legally recognize same-sex relationships and (2) facilitate the free expression of unconditional love toward the partner. In other words, participants indicated that these changes allowed them to make a public (and legal) statement of their commitment and contributed to their own feelings of happiness and well-being. We aim to build upon these findings and examine how Portuguese LG individuals experience their relationship across relationship quality outcomes. To do so, we framed our study by the Investment Model (IM; Rusbult, Martz, & Agnew, 1998).

The Investment Model as a Conceptual Framework
The IM offers a straightforward framework to understand relationships and is one of the most empirically robust models to predict relationship maintenance (for reviews, see Le & Agnew, 2003;Rodrigues & Lopes, 2013;Rusbult et al., 1998). Commitment is defined as a long-term orientation and motivation to persist in the relationship, associated with feelings of psychological attachment to the partner (Arriaga & Agnew, 2001), and is predicted by satisfaction, perceived quality of alternative scenarios, and investments. Satisfaction refers to positive experiences in the relationship and toward the partner, namely intimacy, affection, and attraction. Alternatives refer to any scenario other than being with the partner (e.g., being alone, with friends, with family, or with another person). To the extent that individuals value their relationship, potential alternative scenarios tend to be perceived as having less quality. Investments refer to any type of resource applied in the relationship, whether intrinsic (e.g., time spent together) or extrinsic (e.g., shared assets), that would be lost or diminished if the relationship ended. Greater satisfaction, lower perceived quality of alternatives, and greater investments increase commitment, which consequently promotes happiness and relationship functioning (e.g., trust, couple adjustment; Rusbult et al., 1998), and decreases cohabitation dissolution (Dush, 2011).
The IM has already been extended to same-sex relationships (Beals, Impett, & Peplau, 2002;Greene & Britton, 2015;Lehmiller, 2010;Lehmiller & Agnew, 2006). Indeed, Kurdek (2008) found the expected pattern of correlations between all IM indicators with samples of LG individuals. Furthermore, research has shown that LG and heterosexual individuals report similar relationship quality outcomes (e.g., commitment, satisfaction, love, trust; Kurdek, 1995Kurdek, , 2006Lehmiller & Agnew, 2006;Rusbult et al., 1998), couple adjustment and conflict resolution strategies (Kurdek, 1994(Kurdek, , 2004, and negative experiences when breaking up (Kurdek, 1997). For instance, longitudinal findings have shown that LG individuals (either with or without a legally recognized union) were as likely as married heterosexual individuals to maintain their relationships (Balsam et al., 2017;Rosenfeld, 2014). Still, some differences have also been found. For instance, LG individuals generally tend to report less investments (Lehmiller, 2010;Lehmiller & Agnew, 2006), and less support from family members (Kurdek, 1988(Kurdek, , 2006 and society (e.g., equality of rights; Oliveira et al., 2013;Rothblum, 2009;Scherpe, 2013), when compared to their heterosexual counterparts. This lack of support may result in a greater struggle to endure difficult periods. To compensate for this, however, LG individuals develop strategies to help them maintain healthy and functioning relationships, namely by valuing the support of close friends and their LG community (Kurdek, 1988;Kurdek & Schmitt, 1987) and developing greater resilience (Kurdek, 2004). Another of such strategies might be the decision to cohabit with the partner.

Cohabitation and Relationship Quality in LG Individuals
Cohabitation is considered as one the most important milestones for LG individuals that helps to make a distinction from dating relationships (Reczek, Elliott, & Umberson, 2009), fosters shared responsibilities between partners, and contributes to a healthy relationship functioning. Indeed, research in same-sex relationships showed that cohabitation is a symbolic representation of commitment that helps to create a sense of family and is a way to publicly show how much both partners are committed to one another and to their relationship (Haas & Whitton, 2015). Moreover, cohabiting individuals have the opportunity to spend more time together and share activities, which helps to develop greater emotional and sexual intimacy, and strengthen the role of the partner as an important source of emotional support (Rostosky et al., 2006). Therefore, cohabitation has an important emotional dimension associated not only with the expression of commitment, but also with the perception of being satisfied and invested in the relationship. Nonetheless, the question remains as to whether these benefits of cohabitation among LG individuals are especially evident in countries where same-sex unions are (still) not legally recognized, or if its symbolic significance decreases with the option to legally recognize the union. Research on differentsex relationships may be informative to examine this.
For the most part, cohabitation in different-sex relationship has been seen as a substitute of marriage or a transition phase before marriage (Manning & Cohen, 2012;Stanley, Rhoades, & Fincham, 2011). Research in different cultural contexts has shown that premarital cohabitation is no longer associated with marriage instability, presumably because it is becoming increasingly normative (Manning & Cohen, 2012;Zhang, 2017). Examining differences according to cohabitation status, Rhoades, Stanley and Markman (2012b) showed that cohabiting heterosexual individuals were more committed than their non-cohabiting counterparts, but at the same time less satisfied and as having more negative communication with their partners. The authors also followed individuals over the course of 20 months and showed that non-cohabiting individuals who transitioned into cohabitation experienced a decrease in relationship quality, and an increase in the pressure to remain together. In another longitudinal study, the authors replicated these findings and further showed that the experience of external pressures to stay together were predictive of relationship maintenance, independently of relationship quality (Rhoades, Stanley, & Markman, 2012a). These findings have been explained by the concept of inertia (Stanley, Rhoades, & Markman, 2006). Compared to individuals who have longterm plans for their future together, those without a clear notion of the future of their relationship may decide to cohabit in order to seize an opportunity (e.g., reduce the costs of having two separate homes). This may foster a sense of inertia that promotes relationship maintenance mostly based on the perception of investments and external barriers, and not necessarily on the experience of long-term commitment. Therefore, among heterosexual individuals, cohabitation and marriage are not necessarily different in relationship quality and are not necessarily associated with increases of commitment or satisfaction (see also Tang, Curran, & Arroyo, 2014), but rather with the perception of greater investments, in comparison to non-cohabitation.

Overview of the Study
Our main goal was to examine the role of cohabitation in relationship quality among LG and heterosexual individuals in the Portuguese context, in which same-sex unions are legally recognized since 2001. To do so, we explored differences and similarities between individuals who were not cohabiting with their partner, to those who decided to cohabit but did not legally recognized their unions, and those who cohabit and had their union legally recognized (i.e., being in a de facto union or married).
Past findings have shown that, regardless of sexual orientation, commitment is positively associated with satisfaction and investments, while negatively associated with the perception of quality regarding alternative scenarios (Kurdek, 2008;Le & Agnew, 2003;Rusbult et al., 1998). Even though LG individuals usually report less relationship investments due to external constraints (Lehmiller, 2010;Lehmiller & Agnew, 2006), they also develop strategies to overcome such constraints. Cohabitation is one of such strategies that symbolizes the emotional expression of intimacy, perception of emotional support, and long-term orientation toward relationship maintenance (Haas & Whitton, 2015;Reczek et al., 2009;Rostosky et al., 2006). As such, we expected cohabiting LG individuals to report being more committed, invested, and satisfied in their relationship, while not perceiving greater quality among alternative scenarios, when compared to their non-cohabiting counterparts. Because the legal recognition of same-sex unions was not always a viable option for LG individuals, these presumed benefits of cohabitation should be more evident among those who have (vs. have not) legally recognized their union.
For heterosexual individuals, cohabitation has mostly been associated with increases in investments and decreases in satisfaction and commitment (Rhoades et al., 2012a(Rhoades et al., , 2012b. Based on these findings, we expected cohabiting individuals to report greater investments, less commitment, and less satisfaction when compared to their non-cohabiting counterparts. Because cohabitation has become normative and equated to marriage (Manning & Cohen, 2012;Stanley et al., 2011), we did not expect differences between heterosexual individuals who had (vs. had not) legally recognized their union. Again, no differences were expected in the perception of quality among alternative scenarios.
Lastly, changes in the legislation have been shown to positively impact the relationship outcomes of LG individuals (Clarke et al., 2010;Nico & Rodrigues, 2013;Rothblum et al., 2006). For instance, these individuals acknowledge the importance of such legislative initiatives for their well-being (e.g., greater happiness; Pereira & Monteiro, 2017). Hence, we expected LG individuals to report greater relationship quality outcomes when they cohabit with their partner, especially when they have legally recognized their union, when compared to heterosexual individuals in a similar situation.

Method
Participants A sample of 425 Portuguese individuals (225 women) with ages ranging from 18 to 53 years old (M = 28.38, SD = 6.89) voluntarily took part in the online survey. Overall, most participants were college graduates (83.8%), resided in metropolitan areas (71.1%), reported not to be religious (60.9%), and to have a left wing politic orientation (60.9%). Regarding their relationship, the overall majority of the participants did not cohabit with their partners (46.6%), whereas the remaining were cohabiting and had their union legally recognized (28.9%) or were cohabiting without such legal recognition (24.5%). Most participants did not have children (92.9%).
Participants identified themselves as LG (38.4%) or heterosexual (61.6%). Difference tests according to sexual orientation (i.e., LG vs. heterosexual) across demographic variables are presented in Table 1. As shown, there were gender differences, p < .001, such that there was a greater proportion of gay men among LG individuals, and a greater proportion of heterosexual women among heterosexual individuals. There were also age differences, p < .001, such that LG (vs. heterosexual) individuals were older. Results also showed differences regarding relationship type, p = .035, such that there was a greater proportion of LG (vs. heterosexual) individuals in cohabiting relationships without a legally recognized union. Lastly, there were differences in relationship length, but only for non-cohabiting relationship without a legally recognized union, p = .001, such that heterosexual (vs. LG) individuals had longer relationships. No other differences emerged, all p > .054.

Measures
Demographic Variables The survey included standard demographic information, such as age, gender, education level, and area of residence. Given the goal of our study, we also included more specific questions and asked participants to indicate their relationship status (i.e., legal recognition of the union), if they were cohabiting or not with their partner, and their sexual orientation (heterosexual, gay, lesbian). (Rusbult et al., 1998; Portuguese validation by Rodrigues & Lopes, 2013) and assesses four relationship quality outcomes: commitment (seven items; α = .89 in the current study; e.g., BI want our relationship to last for a very long time^), investments (five items; α = .81 in the current study; e.g., BI have invested a great deal of time in our relationship^), satisfaction (five items; α = .90 in the current study; e.g., BI feel satisfied with our relationship^), and perceived quality of alternatives (five items; α = .83 in the current study; e.g., BThe people other than my partner with whom I might become involved are very appealing^). Responses were given on 7-point scales (1 = Do not agree at all, 7 = Agree completely), and a mean score for each outcome was computed.

Procedure
The study was in agreement with the Ethics guidelines of Instituto Universitário de Lisboa (ISCTE-IUL). An online survey was sent out through general mailing lists (e.g., university students and staff) and those directed at the LGBT+ population, publicly posted on social network websites (e.g., Facebook), and made available in LGBT+ associations webpages (e.g., ILGA Portugal).
Before starting, individuals were informed that they would be taking part in a voluntary and confidential self-report survey about personal relationships, specifically directed at LG and heterosexual individuals. It was explicitly stated that they could withdraw from the study at any point by closing the web browser without their responses being recorded. After providing informed consent (by checking the I agree option), participants were presented with the measures. At the end, participants were Note. Different superscripts (a, b) denote significant differences in column proportions with a Bonferroni adjustment, p < .050. Degrees of freedom for t test varied between 102 and 196.
LG lesbian and gay ***p ≤ .001; *p ≤ .050 thanked, debriefed, and provided with the contact of the research team.

Results
We first examined the overall pattern of correlations between commitment, investments, satisfaction, and quality of alternatives for the entire sample, in order to replicate past findings (Kurdek, 2008;Le & Agnew, 2003;Rusbult et al., 1998). Next, to examine differences in relationship quality, we computed a 2 (sexual orientation: LG vs. heterosexual) × 3 (type of relationship: non-cohabiting vs. cohabiting without legal recognition vs. cohabiting in legally recognized union) MANCOVA on the four relationship quality outcomes. Given the differences in gender, age, and relationship length according to sexual orientation (see Table 1), these variables entered as covariates in all analyses.

Preliminary Analyses
Overall, and replicating past findings, commitment was positively correlated with investments, r = .25, p < .001, and satisfaction, r = .69, p < .001. Investments in the relationship were also positively associated with satisfaction, r = .15, p = .003. In contrast, quality of alternatives was negatively associated with commitment, r = − .39, p < .001, investments, r = − .16, p = .001, and satisfaction, r = − .27, p < .001. This pattern of correlations was replicated for LG and heterosexual individuals separately.
Heterosexual Individuals Heterosexual individuals did not differ in their commitment (Fig. 1), investments (Fig. 2), or satisfaction (Fig. 3) according to type of relationship, all p > .063.

Discussion
LG individuals are perceived to have less intimate and committed relationships (e.g., Cherlin, 2004;Clarke et al., 2010;Lopes et al., 2017;Rothblum, 2009;Scherpe, 2013). Part of this stigmatization may be negatively associated with relationship outcomes, such that individuals in same-sex relationship report fewer barriers preventing relationship ending (Lehmiller & Agnew, 2006). Nevertheless, these individuals report levels of relationship functioning and commitment that are similar to those of heterosexual individuals (Rostosky & Riggle, 2017). Presumably, LG individuals develop strategies to deal with the general lack of social support, including cohabitation status. We focused on cohabitation because it is a proxy of investments that enables LG individuals to increase their intimacy and partner support (Rhoades et al., 2012a(Rhoades et al., , 2012bRostosky et al., 2006), and symbolizes an important step (in several cases the most important one) in the long-term development of the relationship (Haas & Whitton, 2015). Following the changes in the Portuguese legislation regarding same-sex unions, we also questioned if the presumed benefits of cohabitation would be distinct according to whether LG individuals were in a legally recognized union or not.
Our results showed the typical pattern of correlations between all relationship outcomes, providing further evidence for the generalizability of IM assumptions to same-sex relationships (Kurdek, 2008;Le & Agnew, 2003;Rusbult et al., 1998). Our results also showed that both groups of cohabiting LG individuals were more committed, invested, and satisfied than non-cohabiting LG individuals. However, the benefit of same-sex relationship legalization seems to occur for the experience of relationship commitment, but not for investments or satisfaction. No differences emerged in the perception of quality of potential alternative scenarios. These results converge with research showing that cohabitation promotes a  Note. Adjusted means controlling for gender, age, and relationship length.
LG lesbian and gay greater consolidation of same-sex relationships and greater resilience toward adverse times (Kurdek, 2004) and is one of the ways LG individuals have to express their long-term commitment (Haas & Whitton, 2015). There was also a number of differences between LG and heterosexual individuals in similar relationship conditions. For non-cohabiting individuals, there were no differences in investments and satisfaction according to sexual orientation, but heterosexual individuals reported greater commitment than their LG counterparts. In contrast, for cohabiting individuals without a legally recognized union, no differences were found for relationship commitment according to sexual orientation, but LG individuals reported greater investments and satisfaction, when compared to their heterosexual counterparts. For cohabiting individuals with a legally recognized union, LG individuals indicated being more committed, invested, and satisfied than their heterosexual counterparts. These findings converge with the notion of cohabitation as an important step in the development of relationships, particularly for LG individuals (Haas & Whitton, 2015). Interestingly, cohabitation seems to be enough for these individuals to feel satisfied in their relationship. Still, the legal recognition of the union and a public display of dedication and commitment in the presence of close others (i.e., friends, family) might increase their long-term motivation to be with the partner and increase feelings of commitment and dedication.
The lack of differences in investments according to the legal recognition of the union should be taken with caution. Indeed, research has shown that LG individuals tend to report greater intrinsic investments (e.g., intimacy), but not necessarily greater extrinsic ones (e.g., assets acquired together; Kurdek, 2006). This has been explained by a greater difficulty LG individuals have to come up with extrinsic investments (e.g., marriage, adopting children together; Lehmiller, 2010). However, Oswald et al. (2008) have shown that legal ties were associated with the perception of greater external investments and greater barriers preventing relationship dissolution in both same-sex and different-sex relationships. This may be the case of Portugal. However, we were unable to compare both types of investments a posteriori, because the measure used in this study does not allow for an explicit differentiation between intrinsic and extrinsic investments. Hence, to clarify the role of investments, future research should use a more detailed measure of investments (Goodfriend & Agnew, 2008) and complement this with information on normative beliefs about relationships, how long partners cohabit, under which condition they first moved in together, how supportive of the relationship is their close family and friends, and whether or not partners are planning to marry and/or having (or adopting) children in the future. This type of study would also allow researchers to understand to what extent the concept of inertia (Rhoades et al., 2012a(Rhoades et al., , 2012b might also be applied to samesex relationships. Note, however, that our findings do not seem to support this hypothesis. Indeed, cohabiting LG individuals reported greater commitment and satisfaction, and not just investments, than their non-cohabiting LG counterparts. The lack of differences in quality of alternatives also needs to be acknowledged. The IM assumes alternatives as any external situation other than being with their partner, including being with friends or with potential alternative partners. Research has suggested that LG (vs. heterosexual) individuals, and especially gay men, are more sexually unrestricted, and more likely to have a mutual sexual agreement allowing extradyadic partners (that may or may not include their primary partner), without any detriment for love, liking, satisfaction, closeness, commitment, or relationship longevity (Fingerhut & Peplau, 2013;Kurdek, 1991Kurdek, , 2008Peplau & Fingerhut, 2007;Wheldon & Pathak, 2010). Hence, they may attribute less importance to sexual exclusivity without weakening relationship quality. Future studies could also consider how sexual agreements for (non)monogamy are associated with relationship quality outcomes among LG individuals (for evidence on different-sex relationships, see Rodrigues, Lopes, & Pereira, 2016;Rodrigues, Lopes, & Smith, 2017). Relatedly, studies could also examine if discrepancies in sexual attitudes between partners influence relationship quality (for evidence with lesbian individuals, see Markey & Markey, 2013), and how sexual transgressions can harm the relationship.
Our results also showed no differences in either relationship quality outcome for different-sex relationships. Arguably, cohabiting heterosexual individuals may have decided to cohabit without a thoughtful long-term plan, or to marry after cohabiting with their partner, which would converge with the concept of inertia (Rhoades et al., 2012a(Rhoades et al., , 2012b. However, different-sex relationships did not differ in relationship investments. Indeed, these individuals should have reported being more invested when cohabiting with their partner, regardless of having a legally recognized union or not. This lack of significant results may be explained by a confound in the cohabitation measure. In the current study, we used a dichotomous item to assess cohabitation status (no vs. yes). However, recent research has shown that alternative forms of relationships (e.g., stay-overs, living together apart) are not different from permanent cohabitation in some relationship quality outcomes (Willoughby, Madsen, Carroll, & Busby, 2015). Hence, there is a possibility that some of the non-cohabiting individuals were in these nonpermanent forms of cohabitation and did not identify themselves as Bcohabiting.^Future studies should consider this possibility by having a more detailed measure of cohabitation forms, while also examining different types of investments and norms surrounding sexual behavior.
The cross-sectional nature of our data did not allow to directly assess the impact of legislative implementations in same-sex relationships. We compared cohabiting LG individuals who have decided to have their union legally recognized with those who did not have such recognition, which might be an indirect source of information about the impact of such implementations. Our results converge with other findings showing that such changes have a positive influence on the functioning of same-sex relationships (Clarke et al., 2010;Nico & Rodrigues, 2013;Pereira & Monteiro, 2017;Rothblum et al., 2006). Nevertheless, developing a longitudinal study would allow to establish causality and provide a better understanding of whether the IM is a robust model to predict same-sex relationships longevity and breakup for noncohabiting LG individuals and those who cohabit (either with or without their union legally recognized). Such study would also allow to grasp just how societal changes can reduce social marginalization of these individuals and their relationships (e.g., Oliveira et al., 2013). The existence of some demographic differences between LG and heterosexual individuals (e.g., gender, age, relationship length) may also constitute a limitation in our study. Although we adjusted for these variables in all our analyses, there is evidence suggesting that these variables are reliable predictors of relationship dissolution among male-male, female-female, and different-sex relationships (Balsam et al., 2017;Joyner, Manning, & Bogle, 2017;Rosenfeld, 2014). Hence, future research should seek to expand our current sample to include a more diverse range of these individual characteristics, while also including other relationship quality outcomes (e.g., intimacy) and perceived social support for the relationship (e.g., from parents, friends; see also Herek, 2006). Likewise, future research should also seek to include a more diverse sample comprising bisexuals, transgender, and queer individuals, given the scarcity of research among these populations (Clarke et al., 2010). Additional cross-cultural research would also be relevant to fully understand if these results are replicated in other contexts where same-sex unions are already legalized (e.g., Brazil, USA), and which differences emerge when compared to contexts where same-sex unions are yet to be legally recognized (e.g., Venezuela, Poland).

Implications for Social Policies
Our findings may be informative of the impact that legislative initiatives in the Portuguese context (e.g., promotion of equal rights for LGBT+ individuals) had on samesex relationships, and to devise new intervention strategies targeted at promoting greater quality of life among LG individuals. For instance, human-rights organizations can use our results to develop campaigns to inform the general population about the benefits of having equal relationship status, regardless of their sexual orientation, not only for relationship stability but also for well-being. Our results can also inform proposals aiming to improve current bills, such as greater equality in access to family support, clearer inheritance rights in the event that one of the partners deceases, and equality of access to fiscal benefits, to name a few (for a discussion, see Herek, 2006).
Our results might also help open avenues for further understanding the organization of household labor in same-sex relationships and promote the discussion of equality of labor division in this type of relationships at a social policy level. More broadly, our results can be informative for campaigns directed at helping professionals (e.g., social workers) to recognize and prevent discrimination solely based on how samesex relationships are perceived (e.g., stability of the relationship) and its consequences for different social processes (e.g., discrimination in the healthcare system) and legal processes (e.g., inclusion/exclusion from adoption processes).
At an intervention level, our results can be informative to anti-discrimination campaigns, given that recent studies still point to high levels of prejudice (e.g., Lopes et al., 2017) and micro-aggression (Platt & Lenzen, 2013) against LG individuals, as well as minority stress experienced among these individuals (Rostosky & Riggle, 2017). By pointing to the inexistence of general differences in relationship quality outcomes between same-sex and different-sex relationships, our results are helpful to develop new awareness campaigns tailored for the general population, aimed at reducing generalized prejudice and violence, and increasing the well-being of LG individuals. At a more specific level, our results might inform anti-discrimination campaigns by helping the general public in the process of accepting same-sex relationships (Rodrigues, Fasoli, et al., 2017), and at the same time show same-sex partners as loving individuals (Roy, 2002). Despite the introduction of legal cohabitation and marriage rights, social acknowledgment of the affective and loving nature of LG relationships still falls short from desired (Brandão & Machado, 2012).

Conclusion
Our study builds upon the work that has been mainly conducted in the USA (Lehmiller, 2010;Lehmiller & Agnew, 2006) and presents findings from the Portuguese context, where the legalization of same-sex unions was approved almost two decades ago (Brandão & Machado, 2012;Oliveira et al., 2013;Pereira & Monteiro, 2017). One of the soundest finding was that cohabitation among LG individuals is associated with the expression of long-term commitment, and the experience of greater relationship quality. Presumably, cohabitation acts as an extrinsic investment with implications for commitment, intrinsic investments, and satisfaction. However, the legal recognition of these cohabiting unions seems to increase only commitment, and not necessarily other relationship quality outcomes. Hence, cohabitation seems to be one of the greatest milestones, particularly in the development of same-sex relationships and relationship quality, independently of legal recognition. In turn, such decision may have implications for the disclosure of privacy to family members, extended friend network, and/or members of the immediate social network (e.g., neighbors). Hence, the positive effect of cohabitation may extend beyond the individual or the dyad level, and help promote greater well-being LG individuals, as well as more positive interpersonal relationships within their social network.