How to ask him if he's gay...?

[Hayden]

Im 16, he's 16. Im a closet gay. Anyway, theres this guy that I have recently befriended. We talk facebook, text, we have a class together. You know how normal friends do. Thing is I catch him staring at me, his fingers linger when I give him something, you know subtle things. But the problem is, he is like me. Can't tell that your gay, and if you are found out, you deny it. I have asked once if he was gay, he said "wtf?" from there I proceeded to say it was the wrong conversation to avoid anything. Months later I'm more sure that he is gay, his facebook even says it for christ sake! And he's even liked a facebook page "being gay" but he is not open and denies it? So how can I ask him, without offending him? Failing this, how can I talk to him more? I find topics that interest us both but eventually they run dead and I have to find new ones, thing is its really hard to lead the conversation towards these "new" ones, and I really love talking to him so it makes me a bit sad when Im not talking to him... So any thoughts on how to start deep meaningful conversations.... me and him have never really had one?
I'd also like to add, if anyone ever reads this, he is FOR gay marriage and would be comfortable to have a gay friend.