When i was 13yo something like this happened at the school with 3 girls from my class.
Some dude passes by in a van in a small road by the school fence. When he was just passing through he oppened the door of the van and exposed himself ejaculating to the girls.
I found this event amusing like hell when everyone was in shock. I had to hide to laugh out loud. It was about this time i started realising i wasn't normal people.