Mardi Gras Mentality

The act of doing something completely out of the ordinary or utterly embarrassing in front of a group of strangers with the notion that you won't ever see them again anyway making it difficult for them to pass future judgement.

Also known as Burning-Man Mentality.

TJ: I can't believe Jay pissed his pants while playing the piano at the sorority house.

John: Yeah he gets a few beers in him and Mardi Gras Mentality takes over, happens all the time.