Wow, did they really have to write a book about that? Seriously, we guys have a switch with two positions: ON and OFF.
1. He's afraid to get hurt again - Maybe. But we like sex, too.
2. Maybe he doesn't want to ruin the friendship - Lies! Any guy that says that is a liar and/or gay.
3. Maybe he's intimidated by me - We were intimidated by girls when we were in the 3rd grade.
4. He just got out of a relationship - Yep. Which means that we need some...quick.
There's your book. Now throw that shit away.