MASTER HAROLD AND THE BOYS
Hally is talking about his father in an un-respectful way so Sam tells him that he should not refer to his father that way, Hally gets angry and tells him to sh## Up. Willie and Sam should be happy that his father, a white man, is their boss. Hally commands Sam to call him Master Harold like Willie does. Sam says hat if this is what Hally wants, he will never call him anything else again. Hally responds by claiming to be teaching Sam a lesson about respect, that's what servants should do, as his father says. Hally then tells Sam about a joke that he and his father find funny. His dad will say, “It’s not fair,” to which Hally replies, “What, chum?” His dad then responds, “A ni##er’s a#se” (55). Hally pokes at Sam, asking if he gets the joke.
Considering the context of the joke and the fact that Hally spits Sam in the face, it is clear that Hally's intention by telling the joke is to make Sam and Willie feel inferior to him and to white people, mocking the factions of blacks and their work as servants.