"Homer's Enemy," Season 8, Episode 23. The F-word is used many times in this episode. It all starts when Marge gets a call from the school asking for a donation to build an athletic field. Although not a sports fan, Marge donates $10,000 because it's something her family can afford. However, the money is stolen by a former student, who then uses it to buy an army of robots. From then on, it's "F**k" all day long. Homer sees his money gone and goes after the thief, but ends up in a fight with the robot army. When he calls out for help, everyone else does too, causing the city to go into chaos. The police show up just in time to see everything being destroyed by Homer's angry father. Then, before they can do anything about it, Mr. Burns shows up with his army and destroys the police car. Realizing they are hopeless against such powerful enemies, they decide to call in a professional for help. At first, it looks like Lisa has been kidnapped by the robot owner, but she calls out for help instead.