An analysis of descriptions of the first heterosexual experiences of thirty-two 14–17-year-old girls in Jamaica focused on the constructs of sexual agency and ambivalence about having sex. Three key results were identified. First, for many girls, there was no clear awareness of any personal decision-making process or agency with regard to their first sexual encounter. They describe a situation that ‘just happened’. Second, many girls who probably did not want to have sex but felt compelled to do so for some reason stopped short of calling their experience ‘coerced’ or ‘forced’. Third, most girls wished they had been older or had known more about the physical and emotional aspects of sex before their first time. Much of this regret was related to the nearly universal experience of physical pain – usually unexpected – as well as emotional pain (guilt, anger and embarrassment). Implications of the study findings for sex education include the need to help girls better understand what is involved physically and emotionally in a sexual relationship, and address sexual gender norms and how they may create feelings of ambivalence for girls and influence girls' perceptions of agency within an intimate relationship.