Usually, straight guys don't sleep naked in the same bed. Your friend may be curious and may want to explore having some kind of sex with you. That does not mean he is bisexual or gay. It all depends if he likes it or not after he explores. If he keeps coming back for more, then he may be bisexual or even gay. But it may take some time for him to decide about his sexuality. According to your statement, I would guess that something is going to happen between you two. Seems like he is trying to get closer to you and may want more. So it is up to you if you want to go for it to see what happens. If you do that, do it slowly and don't ask him if he is bisexual or gay. That will put him on the spot. Just explore with him and enjoy it. Make sure not to call this exploration a relationship or love. You will scare him off right away. Keep in mind that he is just exploring and he may not go as far as you want him to go. Your friend may back up at any time if you push him too fast to do something he may not be ready to do. If you want a relationship with him and want more than just exploring sex, be careful as that may never happen. You will end up heart broken. So the decision is all yours. I know it is hard to make a decision, but somehow , we all manage to do the right thing if we listen to our inner self. so close your eyes and ask yourself whether or not you want to take the chance with your friend. Good luck!