Martin invites his class to his birthday, but the party goes horribly wrong when everyone gets food poisoning after eating oysters instead of having a birthday cake. Everyone, except for Bart, are sent to the hospital to get their stomachs pumped. Bart soon witnesses Mrs. Krabappel and Principal Skinner making out in Martin's playhouse. Bart tries to tell his classmates about what happened, but Edna and Seymour convinces Bart to keep the affair a secret. Bart is forced to be a chaperone to Edna and Seymour, it soon becomes unbearable for him. In retaliation for being humiliated one too many times by his teacher and his principal, Bart exposes the affair to his classmates and the school staff. Principal Skinner and Mrs. Krabappel are soon fired by Superintendent Chalmers. Bart begins to regret his actions, he tries to get Krabappel and Skinner's jobs back. Skinner decides to lie to everyone that he is a virgin, he and Edna are rehired, they continue their relationship.
—dawsonpersi