I did it with all str8 friends for about 5 years. A few reasons come to mind as to how it happened. First of all, we all lived on the same street and were good friends with each other. We never did it with anyone outside of our neighborhood. Secondly, I don't think that I would have ever done if it weren't for the fact that another guy started it. Even then, I don't think I would have done it exept that prior to the first time, his dick had always been bigger than mine. I didn't even realize that mine had been growing but when I saw that I was about his size, it made me much more comfortable to be seen.