In the film, his plan is to make the money and move out from his sister's place. He apparently sees Tina and his son only once a week. He is respected by his peers, and is friends with Vito, but hated by Pino. He is annoyed about climbing flights of stairs to deliver pizzas and Pino's racism. Mookie wants Sal to pay him his money early, but Sal refuses as he thinks that he won't see him later if he does. Mookie takes a shower at his sister's house while he's still working his shift. Sal gets annoyed by this, saying that he's pushing it, and threatening to fire him.
He is part of the fourth wall breakers sequence, where he is the first person and insults Pino and his Italian background and says: "You dago-wop, guinea, garlic breath, pizza slinging, spaghetti bending, Vic Damone, Perry Como, Luciano Pavarotti, Sole Mio, non-singing motherfucker."
He tells Jade to stay away from Sal, and tells Sal to leave Jade alone, as he think that Sal is a dirty man. When delivering a pizza to Tina, he gets her nude in her bed and rubs ice all over her. When Radio Raheem gets killed by the cops, he gets a trash can and throws it at the pizzeria window, starting a riot.
The next day, he awakens in Tina's bed and goes out and asks Sal for his money, ensuing an argument. He gets his money, and goes back to Tina.