This was amazing. Happened when I was fourteen.
Nearing the end of the school year (eighth grade) we were 'asked' (aka, forced) to take this standardised test for the state. We took the test over the course of three days. Math first, then reading (comprehension) and then writing (grammar etc.). I usually finish tests early, which was bad because we couldn't leave the classroom.
Anyway, after finishing my math exam I has this huge hard on. I had no clue why I was so turned on, I just was. I ignored it and just read a magazine. The second day came round and the same thing happened! Finished early, raging boner. Again I ignored it (although I did stroke it a bit from outside my pants). The third day came, and after I finished my test...BAM! A big woody. I then knew what I had to do.
I slowly unbuttoned my pants and unzipped my fly. I stretched my sweatshirt over my knees to cover up my manhood as best I could. I poked my wang through the fly of my boxers and started fapping away, shaking my leg up and down to avoid suspicion. Now, here's a kid at the end of eighth grade, ready for high school, sitting at the FRONT of the classroom and right next to a beautiful girl.
Needless to say, this operation was very dangerous and lucrative. After a few minutes I felt a surge from my pelvis, here it was, the moment of truth. I had a great orgasm, I almost jumped out of my seat! I caught my cum in my left hand and closed it to a fist (at age fourteen, there wasn't a lot that came out, so it wasn't too bad). I put my cock away, buttoned my pants and zipped my fly. Luckily, the time was almost up, and when the bell rang, I darted to the bathroom and washed up. I still brag about this story to my friends, they can't believe it!
Public school: $0.00
Pencils and pens: $7.00
Sweatshirt, pants and boxers: $60.00
Masturbating in front of a class next to a cute girl: Priceless!!