I was bunking off games one afternoon (it was raining, and I didn't fancy cross country) and came across another lad from the year below doing the same.

In an effort to impress me, he beckoned me into his form room, then proceeded to piss all over a big pile of his classmates' bags he'd arranged in the corner.

Because I didn't want to get into trouble either, I didn't report it, but just walked off and left him to it. Luckily a prefect who was out looking for reprobates skipping games just missed my exit of the room, and walked in to find this chap with his shorts round his ankles, curling one out on top of the already-pissed-on pile.

To be honest, as gross as it was, this kid had been acting up for months. He just didn't want to be at boarding school, and wanted some way to get expelled so he could go home.