Is my friend gay, curious or actually straight?

Ok, so I am gay. I have a friend who is not gay. I'm 25, he's 32. We met during a program at my college that he participated in. I immediately noticed that he was very progressive, and he especially is very interested in white/black relations and gay rights. We became cool. One night while around some friends we were clowning around and kissed as a gag joke. We have never done it again, and he has said that he would never kiss me again unless we were on stage (We are both actors). I took him to a gay club one night where he was hitting on girls who were actually talking to him in a gay club, which I thought was funny. At the gay club we went to before that, he got drunk and asked to kiss me. I said no because I did not want to seem like I was just that easy. When he brought me home, I made it obvious that I wanted to kiss him but he kind of didn't respond to it. He just acknowledged that he knows there are some feelings, but its cool that I understand he is straight and we don't take it there. He has also made comments before about "all people being a little bit gay". I have tried to take him there a bunch of times, I will make slight passes, and he will respond with something like, "Yo, I'm not ready to show you my d**k yet", or "I'm not going to have sex with you yet". Its like our whole friendship straddles this line between overtly gay and just extremely comfortable. He just keeps acknowledging the fact that he knows I have feelings, and he knows that he has some curiosity, but he never acts on it and he is always talking to a bunch of girls. NOTE: He and his wife are recently separated. Then he always adds the word "yet" to the end of his sentence when he says that he is not going to do something sexual. As if to say some day, but not today. It seems like whenever I make a pass he declines, but he does subtle things to let me know he is curious. What is going on? Is he conflicted and not sure? Is he waiting for the right moment and/or day? Is he just stringing me along and dealing with me because he feels like he will hurt my feelings if he explicitly rejects me? Should I just aggressively pursue him one day to see how he will respond? I'm scared that if I do that, then we may end up not being friends anymore and/or we may even fight or something like that.