There was a huge uproar when the "Book of Erotic Fantasy" was announced and published. That allowed this book to fly under the radar. This is a shame, because this book is far better than its more famous cousin. This book as a real GURPS flavor to it. It covers sexuality in gaming in not just a fantasy setting, but in historical, modern, horrow, and future campaigns. The book is well crafted in that even if you are not using d20, you can easily adapt it for your setting. It does have ready made spells for d20, but this is a bonus, not something which draws away from the rest of the book. In fact, this bok is almost a lesson about sex that every teenager could gain from.
Trust me; this is a book required for any decent game library.