As long as you don't put out too soon you'll be fine. Keep dude guessing but not too much where he gets pissed off and is like, "whatever, this chick's psycho" and dips.

So basically once you ask him out, act exactly as if you got asked out once the asking out is done. If that makes sense. Cuz if you keep as the pursuer the male instinct is pretty much to go along with an available option.