Mouth Vesuvius

When you throw scalding coffee on someone's bare ass and immediately try to lick it off

John: Did you hear what Gregg did to Mandy after work last night?

Cheri: What pray tell?

John: The ol' Mouth Vesuvius. But he buried his face so fast and deep that he had to go to the E.R. 3rd degree burns - may be permanently scarred!

Cheri: How dreadful. Say no more.