Sexual desire tends to subside gradually over time, with many couples failing to maintain desire in their long-term relationships. Three studies employed complementary methodologies to examine whether partner responsiveness, an intimacy-building behavior, could instill desire for one’s partner. In Study 1, participants were led to believe that they would interact online with their partner. In reality, they interacted with either a responsive or an unresponsive confederate. In Study 2, participants interacted face-to-face with their partner, and judges coded their displays of responsiveness and sexual desire. Study 3 used a daily experiences methodology to examine the mechanisms underlying the responsiveness–desire linkage. Overall, responsiveness was associated with increased desire, but more strongly in women. Feeling special and perceived partner mate value explained the responsiveness–desire link, suggesting that responsive partners were seen as making one feel valued as well as better potential mates for anyone and thus as more sexually desirable.