When you poop and forget to whipe so it drys in your butt cheeks and you finally aggressively pull the cheeks apart and the poop stays straight in the shape of a disc
"Jerry! I just found biggest poop disc after lunch with karen."
Basically when a chick is riding a guy and tells him that he's penetrating her puxXy but in reality she scoots down and inserts it in her ass without him knowing
But you said :" Ah it's my pussy it's my pussy" , but in reality we had anal!?