Not long after George and Lennie arrive at the ranch, George makes it clear to his friend once again that he should let him do all the talking. Lennie, who trusts George implicitly, goes along. However, this causes difficulty when they meet up with Curley. Curley doesn't understand why it's George who is doing all the talking while Lennie is all clammed-up:
By Christ, he's gotta talk when he's spoke to. What the hell are you gettin' into it for?
Right from their first meeting, it's clear that Curley doesn't understand Lennie or the precise nature of his relationship with George. What's more, he never will, which is no surprise given that Curley is such a narrow-minded individual.
One of Curley's constant refrains is
Any you guys seen my wife?
This quotation is particularly revealing of Curley's character. A jealous, possessive control-freak, he always needs to know exactly where his wife is, and what she's doing. A sexually attractive, alluring young woman, Curley's wife exacerbates her husband's many deep-seated insecurities. Curley won't publicly admit it, but he knows that his wife could do a whole lot better than him. And so the only way he can be sure that she hasn't just taken off and left him is if he knows exactly where she is at all times.
Curley's insecurities are also much in evidence when he asks Lennie
What the hell you laughin' at?
Lennie is just laughing to himself, but because Curley is so insecure, he automatically assumes that he is the butt of some kind of joke.