A new book details 237 different reasons women have sex.
Love, pleasure, duty: Why women have sex - CNN.com
I know there are probably 10 times that number why they
DON'T have sex, the most common being lack of previous sexual partners, by about 3 billion or so. This is proven by the vast number of women who have told me: "You're the last man on earth I'd have sex with!" Obviously they are working their way towards me.
I haven't read the book, so I don't know all the reasons, but I am wondering what would be the 3rd or 4th reason for a woman (I'm assuming being horny is number 1, and because it's just fun/feels good would probably be 2).