Some days being involved in this hobby is about as creepy as sitting at the foot of a stranger's bed and watching them sleep. Being involved in role-playing games shouldn't be something that makes your skin crawl but when you read books like the Book of Erotic Fantasy you walk away from the experience feeling slimy. The problem isn't that sex is involved; it's that there are game mechanics being developed for the act and subsequent results.
Look, I'm no modern day Casanova who's had sex with hundreds of women but I can tell you that having read through this book if you think there needs to be game mechanics on the subject then you're playing the wrong game. Get out to a bar my friend and find a woman to love. Barring that, find one who'll make you forget about being a shut-in for the night and rings your bell.
Just don't ever say, Roll a d20 to see if she came . . .