When someone has anal sex with some ugly bitch and she sucks his dick right after. Later her and some other guy hook up and he kisses her poopy dick mouth, thusly receiving the poop dick mouth.
Puffins are more prone to poop dick mouth than most other animals.
Poop Dick Flakes(PDF) are when you have had anal sex with your penis. After sex, the poop on your penis will dry up. When the poop on your penis dries up, you start losing your boner and the poop wil flake off onto the floor.