A: If you wait longer you may loose him. It hurts bad when that happens. Its happened to me with one girl. So make a move if you know he likes you. You have nothing to loose :-) if he likes you.
A: I've been cheated on many times :-(. It can be where you walk in on the girl screwing another guy. To you can tell signs. Such as spending less time with you, hanging out with "a friend" all the time, less I love yous, fewer phone calls, loss in interest of sex, not wanting to cuddle, anything... more
A: Ive been in this situation but at the guy side. and I always get really shy or am worried about the girl saying no and messing up our friendship. maybe you should give him some signs. or ask him out your self :-)