Parents tend to name all of baby boys' body parts, but with girls they go from belly button to knees with this void in the middle. That doesn't change as kids go into puberty.

I asked a high school girl about unreciprocated oral sex and said, "What if guys were asking you to get them a glass of water and never offered to you a glass of water? Would you put up with that?" She burst out laughing. It never occurred to her.

Girls would say: "I have a boyfriend for that." So in addition to putting their pleasure literally into someone else's hands - an inept teenage boy - these are the same girls who say they do not climax with a partner. It's the opposite with boys; they say because they can do that themselves, girls should perform oral sex.

Sexualization is imposed from the outside as opposed to sexuality, an understanding of the body's responses and desires and ability to communicate that, cultivated from within.

Saying "yes" [to sexual activity] is a pretty low baseline for sexual experience and I wanted to write about what was happening to girls after "yes."

There is a way hook ups are serving young women. And it was important for me to always talk about how behaviours were serving girls, not just making them the victims.

For years we've used the bases analogy - with intercourse being the "ultimate sex" even though that's probably not going to feel good to girls. That model doesn't let you say "I like it at second base, maybe I'll stay here."