The ways in which the discrepancy between one’s own interest in sex and that of one’s partner may affect personal sexual satisfaction has rarely been systematically studied, especially among older adults. Previous research among younger adults indicates that a discrepancy in sexual desire can be detrimental in terms of several relationship outcomes, including sexual satisfaction. This study aimed to investigate a conceptual model of sexual satisfaction among coupled older adults which posits that the association between perceived discrepancy in sexual interest and sexual satisfaction is mediated by the frequency of sexual activity and emotional closeness during sex. Data from a probability-based postal survey that included 2695 partnered heterosexual adults aged 60–75 years from four European countries (Norway, Denmark, Belgium, and Portugal) were used to test the mediation model. Due to expected gender differences in the two mediators, all analyses were carried out separately for men and women. The findings supported the proposed model, suggesting that as an individual’s perception of a discrepancy in sexual interest increases, his or her levels of sexual frequency and perceived closeness during sex decrease—which in turn diminishes sexual satisfaction. The results of this study provide insights into links among sexual interest, sexual frequency, emotional closeness, and sexual satisfaction in older adults, and point to substantial similarities in the sexuality of aging men and women in this regard.