Sexually, what's a girl to do? When I was a teenager in the 1970s, the hottest thing on girl radar was Judy Blume's young-adult novel "Forever." My family was living in Ireland on a sabbatical year when it came out, and so a friend packaged it up (in actual brown paper) and sent me a copy from Berkeley. In Ireland at that time, not even adults could have bought a book like "Forever," let alone girls in their summer dresses. Every time I re-encounter the book, I expect to find an amusing curio, a reminder of a more innocent age. And each time I am surprised again - shocked - at how explicit and intentionally erotic a book it is. The protagonist, Katherine Danziger, was a new kind of girl hero. The 17-year-old daughter of two loving parents, she inhabits a suburban New Jersey household that also includes a bratty but adorable younger sister. At a fondue party, she meets a boy named Michael and they fall in love. In not much time they begin having sex - a lot of it. For a couple of know-nothing young amateurs, they really go to town, and Blume doesn't stint when it comes to providing details. Katherine doesn't keep her sex life a dark secret from her parents, as a girl from a similar background would have done in the 1950s or '60s. They know exactly what she is up to, and they are all for it. We girls loved that book, but "Forever" scared a lot of adults. It described a world in which there seemed to be no injunction against premarital sex for adolescent girls, no assumption at all that sex needed to be associated in any way with marriage or, at the very least, with shame. By the novel's end, Katherine and Michael have broken up, and it's perfectly clear that she will go on to have other relationships with other boys, and that they will be similarly fulfilling, time-limited and emotionally significant. Mere anarchy seemed loosed upon American girl land, and it freaked out a lot of adults, who made "Forever" one of the most banned books in the United States. In fact, however, when read from the perspective of 30 years on, "Forever" describes a world with a strong and morally defensible code regarding girls and sex, a code that naturally aligned with girls' best interests. Katherine and Michael were a couple: a boyfriend and girlfriend in an exclusive relationship who spent lots of time doing things together and getting to know one another well. They respected each other. They were also in love. However ephemeral and immature such a love might be, anyone who remembers his or her own adolescence knows that the emotion is an exquisitely intense one, inextricably bound up with physical desire. Those of us who inhaled the details of Katherine's life during that summer of her debut are grown up now, and most of us have children. I suspect that the ones with daughters assumed they would hand down this code of expectation - one so humane, and so good - to them, freeing them from the hang-ups and limitations of earlier eras. And it would be a snap to ensure that their girls got the necessary information on sexual health and safety for such a code to be a success. Go to an eighth-grade health class and you'll see 13-year-old girls unrolling condoms with the bored efficiency of streetwalkers. But it turns out that providing information is the easy part; helping them develop the expectations of love and commitment as prerequisites for sexual activity is another matter. In the first place, most kids today don't couple up, even if they "hook up." The typical high school girl does not expect to have at least one boyfriend at some point before graduation. I know plenty of young women who have gone through college without having one, often to their great disappointment. As a result, we are seeing a generation of girls whose early sexual experiences lack the elements of emotional commitment and love - and oftentimes even of affection - that are so important for them. Moreover, the ubiquity of hard-core pornography in our culture - a force that is dictated by a set of imperatives at absolute odds with the best interests of growing girls - means that even the youngest adolescent boys are often steeped in sexual images and expectations that are punishing to girls' spirits. Most parents, while they fret about this state of affairs, seem unwilling to engage with it in any meaningful way. Short of demanding chastity or abandoning all expectations of responsible sexual behavior, parents aren't sure what kind of code to pass along to their daughters, who suffer for the lack of one. It is my contention that the experience of female adolescence is emotionally complex, and that parents ought to be deeply involved in helping their girls navigate it. Understanding that their daughters were born into a culture that supports causal sexual contact is the beginning of understanding how dismissive, even contemptuous we are toward adolescent girls. We are inflamed with the concepts of academic and athletic equality, yet curiously silent on the one subject of greatest importance to girls: their need to combine affection and emotional commitment with their emerging sexuality. In searching for guidance on what a right relationship between girls and sex might be, we might do much worse than taking down that old novel and giving it a second look. Caitlin Flanagan is the author of "Girl Land," out this month.