In grade 2 or 3 a mate and I flooded the school toilets by clogging the drains with wet toilet paper. It caused a huge water fight and there was toilet paper/flooding everywhere. The punishment was that I was not allowed to leave class to use the toilets for the rest of the year, no matter what.
Some weeks later in class we were playing some sort of game to do with standing on your chairs, and if you were "out" you had to sit down. The teacher refused several of my requests to use the toilets. I was still "in", in the game, though I soon sat down anyhow. I then crawled underneath my table and all the way to the teacher's desk at the front of the room on my hands and knees, because I had pissed myself. The teacher was stunned, apologised quietly to me, and lead me briskly from the room. He took me to the lost property bin and found me some new pants, and told me to wait about half an hour before returning to class. I later found out he told the class I was in a lot of trouble for some conjured crime, and had to be taken straight to the principal. Good cover Mr G.