pool pooper 

People, usually children, who have bowel movement, or poop in a public pool

Bobby, the usual pool pooper, pooped in the water again, causing everyone in the pool to immediately exit the pool.

pool pooper by johnnyacorn February 14, 2015

Pool Pooper 

A person or persons who prefer to attend pools and pool areas under the cover of darkness to pass bowel movements.

Brian is the pool pooper, I found a floater this morning!

Pool Pooper by Doofus Rick September 20, 2022