A muffin jamboree is a party or social event where the poon to penis ratio is in a majority favor towards the poon spectrum, in laymens terms the opposite of sausage fest
Billy: I felt real uncomfortable last night
Johny: Why bitch (as he puffs on his cigarette)
Billy: I showed up at this party last night and the cooch to cock ratio was way off balance in favor of the cooch
Johny: Bitch you was at a "muffin jamboree" now quit being a biotch and make me a sandwich!