I am talking with a group of five teenage girls about sex. They are all middle-class kids who attend a large, fairly liberal, highly rated high school. They are all decent students with college plans, and are involved in a variety of school activities and clubs. I will talk later with a similar group of boys. All of the kids have identified themselves as sexually knowledgeable and heterosexual, and they are delighted that I've set up access to an anonymous e-mail account for them to write me afterward about anything they're not comfortable talking about face to face. Tell me a story, I've asked of them -- tell me how it is to be a teenager in our sexual world.

I loosen them up by asking about condoms, a word that would have embarrassed me to death as a teenager. But girls are as conversant today about condoms as they are about shoes and belly-button piercings, and proud of their expertise. They all carry a single condom in their purses, just in case. "I've carried one since I was 12," says Amanda, a petite, soft-spoken girl who is on the track team. "Lipstick and a condom, that's about all you need. You can't trust boys." She hasn't actually had intercourse yet, but, she says, "You never know." At 16, she's given blow jobs to five boys. "It was OK, no big deal. A little boring sometimes, because the guys don't say much, and you have to keep sucking until your mouth hurts. I always pretend I'm Drew Barrymore when I do it."

None of the girls swallow. Just the idea of doing so is "gross." They also don't use condoms for blow jobs, because, they reason, they don't swallow. "On my chest, or my face, or his belly, that's the only place it goes," Cara explains. They know all the technical details about safe sex, having been taught in school since third grade that you can die from sex, but they seem to have created their own rules about how it works for them.

Phone sex is very popular with the girls -- they're experts, as they demonstrate with their fake oohs and ahs. "I talk to my boyfriend every night from 11 p.m. to 1 in the morning, after my parents are in bed," Katie says. "And in between talking about school and gossiping, we touch ourselves and talk dirty, and then we come together." Her sophistication when she speaks of this rivals any adult woman that I know.

Maintaining virginity means the same to all the girls: You can do anything you want as long as there's no real penetration. "We joke and call it 'outercourse,'" Cara says. She is a straight-A student and plans to be a lawyer some day. "You know, like the opposite of intercourse. It's everything but the penetration -- all the making out, the blow jobs, the phone sex, masturbating with each other in person, getting naked and sleeping together. All of it is safe sex." Four of the girls are in the technical "virgin" category, but one is not. She is envied by the other girls a bit, because she seems matter-of-fact about having "done it," and not only does she have a good-looking, steady boyfriend of over one year, she also manages to starve herself to stay at size 0.

We get down to the things that matter. Giving acquaintances blow jobs is not a serious concern for the girls. They don't worry much about diseases or pregnancy, and they don't seem to worry about their parents finding out. But they worry a lot about how they look, about being too fat when they get naked, or when their boyfriends go "down there."

"My thighs are flabby," says Amanda, size 2.

"Yeah," agrees Lindsay, perhaps a size 4 at best. "My belly pooches out right below my belly-button ring."

The ideal for every girl in high school, they explain, is to fit into size 0 jeans, a size that didn't even exist 20 years ago.

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