For all his bravado, Curley is actually pusillanimous. In Chapter Three, when he jealously tracks his wife to the bunkhouse and inquires of the whereabouts of Slim and hurriedly pursues him at the barn, thinking he is with his wife, George and Lennie do not follow Whit and Carlson since George wishes to avoid any trouble. Soon, however, Curley's returns along with Slim to whom he explains that he was "just askin'" about where his wife is and "didn't mean nothing." To this Slim replies imperiously that he is tired of Curley's asking him: "You lay offa me." Again, Curley explains, "I jus' thought you might of saw her." However, Carlson notes the tone of apology and fear in Curley's words, so he taunts,
"You let her hang around bunk houses and pretty soon you're gonna have som'-pin on your hands and you won't be able to do nothing about it."
Whirling around angrily, Curley says, "You keep outta this les' you wanta step outside" but Carlson is not in the least intimidated. Instead, he scoffs, "...You're yella as a frog belly" and threatens to really hurt Curley. Perceiving Curley's weakness, Candy joins in, mocking him for his glove that is full of vaseline.
As a bully who finds himself in a threatening situation, Curley looks for someone more vulnerable than Carlson; he sees Lennie and "steps over to Lennie like a terrier," a small dog known for its eagerness for conflict. He accosts Lennie and asks him why he is laughing. When Lennie looks confusedly at him, Curley is encouraged by his mental torpor and declares, "I'll show ya who's yella," meaning he will demonstrate to Candy and Carlson that he is not afraid of anyone because he has selected the large and imposing figure of Lennie as his victim. Of course, this show of false bravery is also foiled as the brute strength of Lennie's hand crushes Curley's fist.