This happened during school while I was on a pass... but I was most certainly heard, and possibly joined...
Lately I've been suspicious that I may have something wrong in my testicles, specifically the right. It's bigger than the other one, and aches often. I know I'm in that stage of puberty (when they grow), but I'm starting to worry that I have cancer, or a swelling problem.
I was sitting in class - a science class, I hate science - and I started to think up some explanations. I thought about the growing pain scenario, etc, but finally wondered if it was because I hadn't masturbated in five days. Now to many people, that wouldn't be a problem, but for me it would. I typically masturbate 2-3 times a day at home, but since my lock isn't working, I've had to quit cold turkey.
Back to the situation, I was sitting there thinking of all the girls I've seen and how these guys were all talking about their having wild sex with their girlfriends, and I got a huge boner. Way bigger than usual. I knew I needed to masturbate. I sat and waited for the problem to go away, and quickly got up to ask for a pass. The teacher signed it and I hurried out and down the hallway to the bathroom. I knew I had to speed up if I wanted to have enough time. It was 1:30.
I quickly entered the bathroom, which was empty, and raced for the stall. I unzipped, took a whiz, and waited. Still nobody there. I then started to think about all the sexual ideas that had given me that huge boner... and nothing happened. It's hard for me to masturbate standing up, period. I never have done it successfully - until this day. I decided I would have to act fast and stimulate my penis in order to achieve it. After about a minute of rubbing, and a few thoughts, I was rock hard.
I started jerking it slowly and heard a little squish noise come off it. I knew it was because of the whiz I took. I wasn't too pleased, as a few seconds later I heard loose footsteps enter, and approach a urinal. Our bathroom in that part of the school only has one stall. I knew I had to be discrete about the noise and not shake my legs. I went at it again and started thinking about how I was probably being noticed... I love that sensation, when you get could get caught. I love the idea of being caught having sex with a woman. I started to get into... the feeling was great. I realized I had probably been gone too long and panicked. I turned around suddenly and vigorously jacked into the toilet. The load came out - unfortunately not as much as usual, due to the standing and not-enough-time issue. But it landed in three spots... my underpants, the floor (splat!), and the toilet (plunk!). I knew someone was in there still... but why this long? Was he also doing it? I hoped not.
I stood and waited for the spasms to stop. I turned around, acted casual (my feet were visible) and zipped up. I waited for the person to wash up. He did, and I heard the paper roll down. Then something un-expected happened... the mystery person threw the paper towel into my stall. I knew this was a signal that he knew.
I sure hope the guy doesn't remember shoes, how embarrassing. In case you were wondering, I got back at 1:41... to a frowning teacher.