The normative influence of parents, close friends, and other peers on teens' sexual behavior has been well documented. Yet, we still know little about the processes through which these oftentimes competing norms impact teens' own sexual norms and behaviors. Drawing on qualitative data from 47 interviews conducted with college-bound teens, we investigate the processes through which perceived parental, close friend, and other peer norms about sex influenced teens' decisions about whether and when to have sex. Although virtually all teens perceived that most of their peers were having sex and that parents were almost universally against teen sex, some teens had sex and others did not. Our findings demonstrate that teens who remained virgins and those who were sexually active during high school often negotiated different sets of competing norms. Differences in understandings of age norms, in close friends' sexual norms and behaviors, and in communication about sex with parents, close friends and other peers were related to different levels of sexual behavior for teens who otherwise shared many similarities in social location (e.g.. class, race, and educational status). While virgins reported an individualized process of deciding whether they were ready for sex, we find that their behavior fits within a traditional understanding of an age norm because of the emphasis on avoiding negative sanctions. Sexually experienced teens, on the other hand, explicitly reported abiding by a group age norm that prescribed sex as normal during high school. Finally, parents' normative objections to teen sex - either moral or practical - and the ways they communicated with their teen about sex had important influence on teens' own sexual norms and behaviors during high school.