yeah i was in a situation like that a few years ago, i was mad about a guy and he appeared to be mad about me, but he was seeing someone and never mentioned anything about her to me, i got it into my head that he wasn't telling me cos he knew i liked him and didnt want to upset me, and nothing more, but i was stil crazy about him, and one night i just blurted it out and asked him about her, he told me it wasnt serious cos he had feelings for me all the time, he had no idea how i felt about him,
moral of the story, if u dont tell him how u feel, it could be a wasted opportunity cos he probably is mad about u too.
it didnt work out with that guy cos we were young and it was our first year of college but it was a lovely experience and im with my fiancee now who is te most amazing guy in the world, we just got engaged last week and im SOOO over the moon