Sexual urges and emotional attachments are not necessarily interrelated. Still, within romantic relationships, intimates typically function as both attachment figures and sexual partners, such that the attachment and sexual systems may influence one another. The present article reviews the reciprocal relation between these two systems. Specifically, previous studies have demonstrated the contribution of attachment processes to the appraisal of sexual interactions in adolescence and adulthood. Other studies have considered the reverse causal direction, focusing on the function of sex as a promoter of emotional bonds and on the circumstances under which this function is more pronounced. In doing so, some of these studies have investigated the role of attachment processes in linking sexuality with relationship quality and in shaping sexual responses to relationship-threatening events. More research is needed to explore the dual potential of sex as a relationship maintenance mechanism and as a force motivating people to pursue alternative partners.