As is evident from contemporary debates about sex education, Americans remain deeply ambivalent about teenage sexuality. While many presume that such reticence is rooted in religion, how exactly religion contributes to the formation of teenagers’ sexual values and behaviors has been poorly understood before now. Does religion really motivate the sexual choices of a significant segment of adolescent society? Are abstinence pledges effective? Is there evidence for a “technical virginity” phenomenon among religious teenagers? What does it mean to be “emotionally ready” for sex? Who expresses regrets about their sexual activity and why? Tackling these and other questions, Forbidden Fruit tells the definitive story of the sexual values and practices of American teenagers, paying particular attention to how participating in organized religion shapes sexual decision-making. Merging analyses of three national surveys of teenagers with stories from interviews with over 250 of them across America, Forbidden Fruit covers a wide range of topics, including sentiment about waiting to have sex until marriage, motivation to pursue sexual relationships, proclivity for same-sex attraction and behaviors, teenagers’ experience of virginity loss, and the frequency of several heterosexual practices. Forbidden Fruit reveals the complexity of teenagers’ sexual decision-making, documenting that religion affects their sexual attitudes, but that it does not often motivate their decisions to act. Instead, religion often accompanies other “secular” reasons for delaying sex, like concern for safeguarding one’s educational future. Forbidden Fruit describes this largely religion-less “middle class sexual morality” in detail, and concludes with a new typology for documenting how religion shapes human action among adolescents and adults. More broadly, however, Forbidden Fruit puts to rest inane fears about rampant teenage sexuality, concluding that most teenage sex is “traditional,” while pointing out new evidence for disturbing trends both in particular sexual practices and how teenagers learn about human sexuality.