I point to this one incident as the first time I might have ever realised I might be gay.
I was on a student exchange in Canada.
The town I was placed in was very small, I played hockey and once a week there was this "drop in" scrimmage. So because it was a small town, everyone went to it. Including some teachers from school. I remember leaving the locker room after playing and the PE teacher stopped my friend and I - he wanted to talk to my friend about something. He was late 40s maybe early 50s, used to be a muscle builder - was a champion at it at one point in his life apparently.
He was completely naked.
As he talked to my friend he used the towel to fondle his cock and balls "drying" but yea, before I realised it I had a raging boner in my pants.
I didnt understand what was going on but have fantasized about him ever since.