a wet one
A wet one is when you rip ass so hard, it sounds like you just took a dump in your pants, and no one believes you when you say it wasn’t a shart.
"He ripped a wet one so loud, the teacher thought he had a monster in his pants."
"She ripped a wet one and now her pants smell like a sewer."
"He ripped a wet one so hard, the whole school heard it."