14x21 - The Simpsons

After destroying Flanders' shrine to The Beatles, Bart and Milhouse are punished by being put in community groups. Bart joins the Pre-Teen Braves along with Ralph Wiggum, Nelson Muntz and Database. Led by Marge, they start engaging in community activities. However, they soon become rivals with The Cavalry Kids, led by Milhouse. The two groups try to outdo each other and become involved in a contest to sell the most candy. The Cavalry Kids win the prize of singing the national anthem at a baseball game. However, the Pre-Teen Braves pretend to be The Cavalry Kids and sing their own version of the national anthem. As the crowd becomes enraged, the real Cavalry Kids arrive and a massive stadium-wide brawl erupts. Marge becomes upset, and the fighting ends when an image of her crying is shown on the JumboTron.