Much of what is known about emotions and sexuality explores the relationship enhancing qualities of positive affect. This research extends the current literature by focusing on the association between negative feelings and sexual thoughts and experiences in the context of close relationships, controlling for the effect of positive feelings. Specifically, the unique effects of daily negative feelings toward one's partner in general and specific negative feelings (i.e., anger, anxiety, and sadness) on the sexual experience of heterosexual, gay male, and lesbian relationships were explored. Participants completed an initial questionnaire followed by daily diary measures for 14 consecutive days. Positive feelings were positively associated with sexual variables as expected. Negative feelings were associated with increases in sexual behaviors for heterosexual men and women and gay men, but not lesbian women. Sadness showed a unique positive association with arousal, lust, wanted sexual behavior, and sexual behavior for heterosexual men and women and gay men, but not lesbian women. Neither anger nor anxiety was uniquely associated with the sexual experience for heterosexual or same-sex couples.