Why is Curley hostile towards Curley’s wife?

Curley's hostility comes from the fear that his wife, who walks around the bunkhouse and the barn where workers are, will flirt or even engage sexually with these men, and, thus, embarrass him as the boss's son.
In Section 2, Curley's wife appears in the doorway of the bunkhouse. She is heavily made up with red lips and red fingernails. She wears a house dress and pretty red heels. "I'm looking for Curley," she says in a nasal tone. But in the next sentence, she addresses George and Lennie and leans her body against the door frame as she inspects her nail polish in an affected casualness. Because she is flirtatious and the only woman on the ranch, Curley is very jealous. Consequently, he feels he must always prove his virility by being pugnacious. For instance, when he sees Lennie, who is a much bigger man, he challenges him. Since Curley feels that the other men may pose a threat to him, he is on edge. Because of this anxiety about what his wife may do, he is hostile toward her.