Contextual models of relationships and recent theories of attachment system activation suggest that experiences that promote intimacy, such as sexual intercourse, may moderate the negative implications of attachment insecurity. In two independent studies, 207 couples reported their attachment insecurity, the frequency of their sexual intercourse over the past 30 days, their expectancies for their partner's availability, and their marital satisfaction, and in a 7-day diary they reported their daily sexual and relationship satisfaction and their expectancies for how satisfied they would be with their partners' availability the next day. Attachment avoidance was unrelated to marital satisfaction among spouses reporting more frequent sex, and attachment anxiety was unrelated to marital satisfaction among spouses reporting more daily sexual satisfaction. Both effects were mediated by expectancies for partner availability. These findings suggest that the effects of attachment insecurity are not immutable but vary according to the context of the relationship.