What do books have to do with sex? Are the paperbacks having title-to-title contact with the hardcovers in the aisles of the bookstore? Are stacks of books getting it on in some massive literary orgy? Could the two books pressed up against each other in the corner be having more fun than we imagine? Can we even contemplate what might be going on in the library? No. Let's not go there. Books don't have sex with each other, or gender, for that matter, so what's this secret sex about? It's true that many books are about sex or involve sex in some way, but we're not talking about content. Why...