Well ask her what she is thinking about and how her day is going play with her hair let her lay in your lap then kiss her for no reason just don't talk about make up or shopping girls get enough of that from their friends

Some of the signs to help you tell is if she has been acting detached lately, doesn't say that cute stuff to you any more, and if she has been trying to avoid you.

Well it ussually depends on who the guy is if he is known to be a player he actually might want a serious relationship or he just wants to hit that and if hes sweet he probably wants to get lucky