Surprise! Teens Have Sex!
Cory Doctorow’s young adult novel Little Brother is the tale of a 17-year-old who leads a guerilla army of teens against an oppressive U.S. government. Doctorow was surprised to receive critique from parents not because of the rioting and torture described in the book, but because the main character loses his virginity during the course of the story and at another point, has a beer.
An excerpt of his essay Teen Sex follows:
First, because teenagers have sex and drink beer, and most of the time the worst thing that results from this is a few days of social awkwardness and a hangover, respectively. When I was a teenager, I drank sometimes. I had sex sometimes. I disobeyed authority figures sometimes.
Mostly, it was OK. Sometimes it was bad. Sometimes it was wonderful. Once or twice, it was terrible. And it was thus for everyone I knew. Teenagers take risks, even stupid risks, at times. But the chance on any given night that sneaking a beer will destroy your life is damned slim. Art isn’t exactly like life, and science fiction asks the reader to accept the impossible, but unless your book is about a universe in which disapproving parents have cooked the physics so that every act of disobedience leads swiftly to destruction, it won’t be very credible. The pathos that parents would like to see here become bathos: mawkish and trivial, heavy-handed, and preachy.
Second, because it is good art. Artists have included sex and sexual content in their general-audience material since cave-painting days. There’s a reason the Vatican and the Louvre are full of nudes. Sex is part of what it means to be human, so art has sex in it.
Sex in YA stories usually comes naturally, as the literal climax of a coming-of-age story in which the adolescent characters have undertaken a series of leaps of faiths, doing consequential things (lying, telling the truth, being noble, subverting authority, etc.) for the first time, never knowing, really knowing, what the outcome will be. These figurative losses of virginity are one of the major themes of YA novels  and one of the major themes of adolescence  so it’s artistically satisfying for the figurative to become literal in the course of the book. This is a common literary and artistic technique, and it’s very effective.
… Adolescents think about sex. All the time. Many of them have sex. Many of them experiment with sex. I don’t believe that a fictional depiction of two young people who are in love and have sex is likely to impart any new knowledge to most teens  that is, the vast majority of teenagers are apt to be familiar with the existence of sexual liaisons between 17-year-olds.
Should sex be a part of young adult literature?
Information via Locus Online.