Ask him out if he says yes then he's gay.<br />
Also, why the does it matter?
so ask him out, if he says no forget him, there's plenty of gay and bi guys out there.
Just ask in a polite way?
If he isn't gay it sounds like he is at least comfortable with it. No reason not to be open about things. You could flirt and see where things go.
Tell him you don't swing that way.
It would help if you provided some context. Can you explain why you have this question?
What if he is?
If he is good dresser he is
Hm... sounds like he is curious. Hang out with him, and get a feel for how he really feels. Move slowly, and make sure he is comfortable... Drop hints, and if you get on the subject of sexuality, just tell him it seems like he is curious. If he is, and has never explored his sexuality, he is probably still somewhat intimidated or scared. You should be a friend to him first (I remember the first woman I was with was like that, and it helped a lot). I am Bi... It takes time to accept even that, and some people aren't totally open to their own sexuality at first.