Jacking on the bus
When I was 13, I rode the bus. I would near the back and there were only a few people on the bus. I would get h**** and push my p**** through the leg hole my shorts so all my c** would hit the floor. I did this often enough that the bus driver narrowed down his suspects of who the pervert was.
I got on the bus and after going a few blocks, he stopped the bus. He walked back to me with a box of tissues and announced very loudly, "Look boy, if your going to pleasure yourself in public, don't leave any mess on our floor." I was flushed with embarrassment. An old woman about 4 rows made it worse by saying "Now boy, thank the bus driver for giving you tissue."