How do I know if my friend is gay?

My really good friend and soon to be roommate has done some things that make me believe he is gay. (which i hope that he is) I am still in the closet but am DYING of messing around secretly with a guy, Ive never done it and want to so bad. BUT the things he has done are as follows... He saw a nude picture of me and said that "his respect for me went up about 10 times what it was" and he told everyone that he came across for a month after how big I was. Then while I was on vacation, he and my girlfriend at the time were hanging out and he said to her "I really wish (my name) was here so we could have a 3 sum." and when ever we are around each other he will always put his head on my shoulder and put his hand on my thigh, when i jokingly pull his hand closer to my crotch he pulls his hand away quickly. Another time I was testing him and asked if he would take some nude pictures of me to put in a calendar as a valentines day present and he had absolutely no problem with doing so (he is a photographer) and I have asked him things like "would you ever let me give you a ******** even if the lights were out and you pretended I was a girl" (which i made seem like a joke afterwards) and his answers were an immediate no but that could just be because he as well doesnt want anyone to know. I dont want to ask him if he is gay though because like I said I am in the closet (bisexual by the way) and if any of my friends found out then my life as I know it would be over, not to mention that my family is a strict catholic italian family and would disown me. He has had sex with about 6 girls and to my knowledge has never done anything with a guy, not even a kiss. PLEASSSEEEE help me I need to know so bad... by the way Im 20 years old and he is 18