["Family Relations, Volume 75, Issue 2, Page 1294-1311, April 2026. ", "\nABSTRACT\n\nObjective\nThis study examines the association between sexual minority identities, stress, and three dimensions of romantic relationships: satisfaction, conflict, and instability.\n\n\nBackground\nA majority of research on sexual minorities focuses on differences between same‐sex and different‐sex couples. Sex composition is not the same as sexual identity, however. Within same‐sex or different‐sex couples, there are heterogeneous sexual identities. Their potentially unique associations with stress and relationship well‐being remain overlooked.\n\n\nMethod\nThis study analyzes a sample of 3,061 respondents from the National Couples' Health and Time Study, a quantitative dataset of U.S. residents that oversampled individuals with sexual minority identities. The associations between sexual minority identity, stress, and self‐reports of relationship outcomes were determined using a series of nested ordinary least squares regression models.\n\n\nResults\nResults show that sexual minorities as a whole report worse relationship outcomes than their heterosexual peers but that this finding is driven by those with a bisexual identity. Further, stress fully mediates the association between bisexual identity and reports of lower relationship satisfaction and greater conflict. Stress only partially explains the greater levels of relationship instability reported by those who identify as bisexual.\n\n\nConclusion\nThe findings from this study illustrate heterogeneity among sexual minorities and indicate that individuals who identify as bisexual experience increased relationship instability compared with those who identify as heterosexual and those who identify as gay or lesbian.\n\n\nImplications\nFindings implicate the need for additional resources to support individuals who identify as bisexual and their romantic partners.\n\n"]