Think of an absolutely awesome party abruptly and absolutely ruined by the arrival of your grandfather along with his comments about the insolent and hopeless youth. Well that's a royally grandpa-pee'd moment.
Well a grandpa-pee'd moment is pretty much obvious, you cannot miss it when it strikes down on you.
Definition 1: A reply to be used when someone thinks they have the answer to a question but another individual participating in the argument proves them wrong with a detailed and knowledgeable answer with no sympathy for the other original participant's dignity or reputation.
Definition 2: A reply to be used when someone replies to an insult or argument with a flawlessly epic one liner or put down.
Example: "You've just pee'd in my cornflakes."
A very common misspelling of the word, "peed" .
Josh had to go so badly, he simply pee'd behind a parked UPS truck.