Using the National Longitudinal Study of Adolescent to Adult Health, this research examines the association between timing of oral sex initiation and marital and cohabiting relationship satisfaction among young adults. Findings indicate that women who transition to oral sex "late" or who have no oral sex experience report higher levels of relationship satisfaction in their current coresidential unions than do women who transition at a "normative" age. Higher levels of relationship satisfaction among women who transition "late," however, appear to be explained by their lower likelihood of experiencing forced sexual relations and sexually transmitted infections. We find no evidence of any association between timing of oral sex initiation and relationship satisfaction among men. To best promote healthy relationships, researchers, practitioners, and educators need to better understand the various types of sexual activities in which young people engage.