I loved that part, actually. And I thought the use of the word "slut" was sad and appalling, but appropriate. I do think, for 16 year olds, it was all fine. But many a 12 year old is reading up to this poing.
I'm not much for censorship, even for kids. Generally, I think if they can understand something, they can read about it. But the book definitely kicked things up, and it was the first time I thought, "Wow, some kids are not ready for this."
I certainly would have been totally fine and prepared to read a book like this when I was in high school.
Spoiler:
Yeah, I was fine and dandy with it all, I hear and see much worse everyday at school. However, I think the book is a little intense for some of the kids I saw in line with me. I was surprised at the content of this book compared to the previous ones, espcially the references to flipping people off and swearing, considering this book is intended for a 10-12 year old audience.