Once when I was about 10 years old my brother was having a bath and I decided to play a little trick on him. That is, I was going to sneak up on him and fart on his face while he was having a quiet soak in the tub.
Fast forward 30 seconds, and I had my bare ass next to his face. His eyes were closed, this was my chance. I tried my best to blast out a steady stream of gas but I accidentally squirted some liquid shit, followed by a number of solid chunks, onto his cheek and into his ear. It was funny because he didn't really know what happened for a second, then he touched his ear and smelled his hand and freaked the fuck out.