Flirting colleague - now feel used?

You have to accept that what he said about not liking you is true, you can't make someone admit they like you, if he does. So either way you just have to act like he doesn't like you. Pretend he's straight, haven't you ever wanted a straight man? Act as if that is the case. If he ever makes a move on you, turn him down, it'll be a total slap in the face, or even better, complain to your boss. lol