It must be a kind of high or rush for a guy not to let his feelings show or be known. If he is uncertain of his own feelings then he may be scared. Most guys are scared of committing to a relationship, not knowing what to expect or what may be expected of him. Yes, a guy can hide his feelings, but not very well. Just the fact he is coming around you is proof he has some kind of feelings for you.
Yes us men can hide our feelings but for how long I do not know. I can't hide my feelings forever. Maybe he is one of those guys who talk to a different girl every week those kinds of guys piss me off!