Verity Brown I don't see any problems at all for 15-year-old. Frankly, if a reader isn't old enough to get the jokes, this book isn't going to corrupt them. And if they are old enough to get the jokes, they're already corrupted.
Lexie This skirts the line I think. While there's nothing explicitly stated, there's a lot of references to sex, and some fade to black wink wink nudge nudge scenes. There's some cursing, but nothing worse then what you'd see on Prime Time TV and well written fight scenes.