when one person poops in their partners ass and then their partner poops into theirs and the sequense is repeated
Jack and Jill used to Poop back and forth for hours till jack started to stink.
When someone poops into someone elses butt-hole, and then they poop it back into their butt-hole, with the same poop. Forever.
"Like I'll poop into her butt-hole. And then she'll poop it back... into my butt... hole. And then we'll just keep doing it back and forth. With the same poop. Forever." Poop back and forth.
When two people line their assholes up facing each other, and one poops into the others asshole, and then the other person poops right back into the first asshole, and this goes back and forth for as long as they want.
Bob: "Me and this girl poop back and forth regularly"
Mike: "Holy shit, does it hurt?"
Bob: "It felt like I kept sitting in mud"