A contest in which two men stimulate each other sexually by masturbation or other means to see who can delay his orgasm the longest. Traditionally, the loser or his spouse(if present) gets fucked by the winner. Usually performed in front of an audience to increase the loser's humiliation.
Bart won his cockfight with Ben by making Ben cum first while everyone watched. His humiliation was complete after Bart fucked his ass and jizzed on his face while the audience jeered.