My best friend and I were 13 and it was a saturday afternoon at the local pool. We were just mucking around and checking out the girls when my friend mentioned he needed to jack off cause the girls in their bikinis were turning him on.
We had never talked about masturbation before but I had a feeling that he did it.
So I mentioned that I was horny too and that I had a boner. He suggested we go to the toilets, so I had to reach into my pants and adjust myself. We got out and in the toilets all the stalls were taken so we entered the only one left and it had a shower and toilet in there.