To act or behave incorrectly with
shellfish. When you preform
something incorrectly and/or
objectively wrong with any kind of shellfish, including crustaceans, mollusks and certain species of echinoderm.
Person A: "Dude, I think I just
committed a scrumpo with my
shrimp scampi."
Person B: "Oh god, do not tell me you..."
Person A & B "...left the tails on..."
Person B: "..oooOOh MY GOD, you
disgust me."