Is my friend straight? ?

ok guys my friend is weired then the rest of the people in my group. He likes to hump boys ALOT, like ok a straight kid will joke around but he does it in public and everything, he likes to touch our bodies when were in the swimming pool and that is PUBLIC aswell, the other day my friend asked his girlfriend y r u hanging around with him so much and she says "because he is like a big girl thats why we get along so well" he is complaining that he is fat (which he aint) and he started talking like feminine kinda "aww thats cute....look at that doggy:....haha wall-e is going into his little spaceship" would u guys say his gay, ive asked him a few times but he says his not i think he says that because we sometimes tend to tease gay ppl a bit so he might be afried. This wont break relationship as mates at all but y wont he come out of the closet. Also he likes to say gay stuff but we dont know if his joking or not like "ooo id so **** that guy"