I had just done it about three weeks ago and I was at school. It was my Gym class and there was a really hot boy I liked in the class his name was Andy. I was watching him the entire class and thinking of different things that I would do with him.
After a couple of minutes of this I got really horny and snuck out of class. In my school kids never use the showers because they stopped working. They are in seperate little rooms in the locker room so you can't see in unless you walk in a little doorway, so I thought great place! I walked into the locker room and walked around and made sure nobody was in. Nobody was so I got into the shower room and pulled down my shorts and started to stroke my really hard dick.
I could see into the locker room a little if I got into the corner by the door. So I watched just to make sure. So a few minutes of stroking went by and when I was just about done I heard the door open so I pulled them up and got in the corner more so nobody could see me. I still had a boner and the sight of guys changing wasn't helping so I started again. I pulled out my dick and started. About half way through I looked out and saw Andy standing there with his dick hanging out the little hole in the front of his boxers. After that it took only a few seconds and I shot all over my hands and the floor and the front of my gym shorts, it took everything I had not to make any noise. It was great, as soon as the locker room emptied I got changed and wiped off the front of my boxers, until after school, then I washed them. I still do that every once and a while, except without people coming in, that was scary.