Mister Poopy butthole

When one person puts their butthole against another person’s butthole, and fornicates by pooping in their butthole.

Dude 1: Hey bro, Sarahlynn came over yesterday and I gave her a Mister poopy butthole.
Dude 2: Nice man, did she know what it was?

Dude 1: Yeah and she was excited too because she’s into shit play.