Sex is integral to maintaining a satisfying long-term romantic relationship such as marriage. It is thus important to identify the factors that promote sexual satisfaction in these relationships. To this end, we examined the extent to which a crucial evolved individual difference-sexual disgust sensitivity-impacts people's sexual satisfaction and relationship satisfaction. Using a two-year longitudinal study of 102 newlywed couples (204 individuals), we demonstrated that, rather than exerting main effects, the interaction of both couple members' sexual disgust sensitivities was indirectly associated with marital satisfaction through sexual satisfaction. People whose partners' sexual disgust sensitivities were relatively similar (versus dissimilar) to their own maintained higher levels of sexual satisfaction across the first two years of marriage, which was associated with similarly elevated marital satisfaction. Not only do these findings highlight the importance of integrating evolutionary perspectives and relationship science, they underscore the value of conducting dyadic research to examine the unique intersection of both couple members' characteristics for people's relationship outcomes.