16 at the time
When I was in 10th grade, I was diagnosed with severe clinical depression. As a result, I missed a lot of school. On one of the days that I had missed, there was a test in chemistry. So when I went back to class, I had to take the exam.
The class had about 25 people, myself included. The class was doing a mini-lab, and was walking around the room. I picked a lab station to do my test, and started working.
For some unknown reason, I started to get really horny. Seeing how I was in the back of the class, I opened my jeans, and started jacking off. It was a huge thrill jacking off back there with everyone, including the teacher, walking around. At any moment, I could be caught. Being as horny as I was, I didn't care. I just kept stroking my cock.
After about 10 minutes, I started to feel my orgasm come close. I edged for about five minutes, then blew my load inside a bar storage hole. I zipped up my jeans, and then finished the exam.
About a week later (I missed the rest of the week) I went back to where I jacked off, and I saw the dried cum. Then I started getting horny again, but I decided to wait until I got home so I could properly blow my load all over face, chest and porn magizine.