We know more about parent and peer influences than about the ways in which specific qualities of adolescent romantic relationships may influence sexual decision-making. Using data from the Toledo Adolescent Relationships Study, we focus on communication processes and emotional feelings, as well as more basic contours of adolescent romantic relationships, including power and influence dynamics. Controlling for traditional predictors and duration of the relationship, results suggest that subjectively experienced relationship qualities matter for understanding teens' sexual behavior choices. Further, findings indicate a similar effect of most relationship qualities on male and female reports of sexual behavior. However, influence and power dynamics within the relationship were not related to the likelihood that boys reported sexual intercourse in a focal relationship. In contrast, girls who perceived a more favorable power balance were less likely to report sexual intercourse than their female counterparts who perceived a less favorable power balance. Recognizing that the results capture reciprocal influence processes, longitudinal and qualitative data are used to further explore the complex nature of these associations.