And he doesn't need to risk bringing you around only to have them say something they shouldn't. If he avoids it like the plague, you'll know something is up.
When we have a crush on someone, it can be hard to see them for who they really are, especially if that person is a player. They’re a little manipulative and they know how to get a girl to fall hard. If he's all about hooking up, that could definitely mean that he's just using you for sex or a steamy makeout sesh. The next time he asks if you want to hang out, say, "how about we go see a movie/grab something to eat?
" If his response is something like, "I'd rather just hang with you at my place :)" or there's no response at all, that shows that he just wants to hook up.
He'll tell you stuff about his life and his past and maybe even open up to you - and he'll ask you questions as well.
If he's not doing that and your conversation is limited to what happened at school that day or you two just watch TV without really talking much, that probably means it's because he doesn't really care.
She's probably trying to look out for you and you should probably listen to her.