Don't let the movies fool you into thinking it's something that always comes with sparks and fire. No, if it's the wrong person, and it's not welcome, it may really come out badly and you could mess up the progress you might have made toward him warming up to a relationship with you. Unless he shows clear signs of being open to you approaching him that way, please don't.

I'm a reserved person and that could really ***** with my mind if someone did that to me