I know this is a strange concept but have you ever masturbated in front of / into a urinal?I tried it once when I was 14 in a high school bathroom and I have to say, even though gross, I enjoyed it.
Masturbate into a urinal?
I dare say that you probably weren't the first and most likely will not be the last.
when i was 15, and my friend was 13, we started to jack off together. several times he and i jacked off at a park in the restroom. into a urinal. felt ok, but not as good as doing it in my room at home