The current research examined the role of post sex affection in promoting sexual and relationship satisfaction in ongoing romantic partnerships. Since romantic partners view the period after engaging in sex as an important time for bonding and intimacy, we sought to determine if and how the duration and quality of post sex affection might promote satisfaction in romantic relationships. In two studies, we tested the link between post sex affectionate behavior (e.g., cuddling, caressing, shared intimacy) and sexual and relationship satisfaction. In Study 1, a cross-sectional survey of individuals in romantic relationships (N = 335), duration of post sex affection was associated with higher sexual satisfaction and, in turn, higher relationship satisfaction. In Study 2, a daily experience study of 101 established couples (N = 202) with a 3-month follow-up, day-to-day changes in post sex affection duration and quality were associated with both partners' sexual and relationship satisfaction, and engaging in longer and more satisfying post sex affection over the course of the study was associated with higher relationship and sexual satisfaction 3 months later. In general, the pattern of results was consistent for men and women, but the association between the duration of post sex affection and relationship satisfaction was stronger for women than for men (Study 1) and women, but not men, felt more sexually satisfied when their partner reported higher quality post sex affection (Study 2). The findings suggest that the period after sex is a critical time for promoting satisfaction in intimate bonds.