Well I wouldn't consider myself completely straight, but I think I know what may be part of the criteria for guys to get turned on by another guy. For me it is a close friendship with a guy I think is attractive and interesting as a person. I have to trust the guy completely that he wouldn't hurt me or use our closeness to manipulate me. I think many guys want a tight friendship but don't know exactly how to go about that without seeming weird. The sexual aspect of the whole thing might come later. The initial vulnerability of one guy to another seems to be the sticking point for most straight guys.
One thing I don't understand about some men is they evidently have never been hugged in the home they were raised in growing up. I have hugged guys and it means nothing more than I care about you, you are special to me, I enjoy your friendship etc. I went by the receiving line in our church one time to tell a young minister how much I enjoyed his sermon and trying to hug him was like trying to hug a refrigerator! He was about as cold as a fifty pound block of ice. I could not believe his body language when I try to hug him which was nothing more than to encourage him. His response was offensive and I just thought to myself, "you have a lot growing up to do and a lot to learn." He played football in high school and had not even graduated college. He just played high school football. He was not a football star or anything near that, but by his response you would have thought he was a football star in the NFL or something. What is it about some men that they think touching another guy is touching poison ivy? I was telling my wife last night about my brother n law and how sweet of a man he was. He is as masculine as they come but has a heart of gold and has a gentleness about him that is precious. I don't know of anyone that has a bad word to say about him. Everyone loves him. everyone. What wrong about that? Nothing! Some men need to purchase a book on how to relate to others and that includes touching!