A type of party derived from the book Private by Kate Brian. A fat phoebe party is a party thrown by a friend for a friend when they are depressed. In this girls only party, chocolates, sweets, and champagne will be consumed.
Friend 1: My boyfriend broke up with me!
Friend 2: What? That JERK! It's okay, we can throw a fat phoebe party. Get out the cake and champagne, and spill girl, you have lots to talk about.