When Cliff wins some innocuous Postal award, he needs a date for the banquet. He asks Diane but she has her cheese club that night. They don't just eat cheese, they talk about it. So he bribes Carla to go with him. Soon, Diane feels guilty and agrees, leaving Cliff with a dilemma. What transpires is hilarious. He finds a different date for Carla and it's superb. We see all of Carla's worst traits portrayed, especially at the end.