This is perhaps the most grown-up book in the series so far. It teaches some valuable lessons that most teens would probably ignore, but the great Cathy Hopkins is right.
In this one, Izzie meets a right douche of a boy, Josh. The cool guy isn't so cool, he's a manipulative liar. One of the biggest lessons in this book is not to let people pressure you into doing anything you don't want to. And a smooth talker is usually a dickhead in disguise.