What does the incident in scene 5 of "Of Mice and Men" reveal about the characters Lennie and Curley?

Steinbeck, who in his youth came into conflict with his exacting mother, often portrays women as Eve-types.  Such a woman is Curley's wife.  Craving attention, she enters the world of the men, the ranch house, first on the pretext of finding her husband.  In Chapter 5 as the men play horseshoes outside, she sneaks into the barn and catches Lennie holding his dead puppy.  In a panic, he shovels hay over the puppy to hide it. From her previous encounter with Lennie, she knows that he is dim-witted, but is also excited by his brute strength, so she reveals to him that she knows what has happened to Curley's hand.  But, Lennie, who fears her because of George's warnings, refuses to talk to her.  Curley wife then takes advantage of his silence and talks to him. Still, Lennie tries to resist her temptations to talk:

'Well, I ain't supposed to talk to you or nothing.....George's scared that I'll get in trouble.'

With this confession, the temptress moves closer to him, speaking "soothingly" about the dead puppy.  She tells him that he can talk with her since the other men are preoccupied with their games.  When Lennie persists in his resistance, she becomes angry, insisting that she is doing no harm.  She speaks of her wish to be an actress and reveals that she really does not like Curley; however, she is not worried about Curley finding out since Lennie is slow and will forget what she has said.  Having thus confided in Lennie, she moves closer. Weakening under her feminine wiles, Lennie "sighs deeply," and continues his ritualistic recitation about rabbits revealing his witless conditioning.

Learning that Lennie loves to pet soft things, she tempts him with her hair, enjoying domination of a man. But, when Lennie becomes too rough, she cries out, making Lennie angry.  He has become afraid that George will hear, so he tries to quiet her by shaking her.  Unfortunately his brute strength has broken her neck.  "Bewildered," Lennie finally concludes, "I done a bad thing,...George'll be mad."  To symbolize the evil of Curley's wife having lured Lennie into his sin, Steinbeck describes her as lying "with a half-covering of yellow hay" with reddened lips parted. [yellow as symbolic of evil.]

When Curley learns that his wife is dead, he does not even bend over her body, the source of his sin, too.  Instead, he seeks revenge upon Lennie:

'I know he done it.....I'm gonna get him.  I'm going for my shotgun....I'll shoot 'im in the guts.'  He ran furiously out of the barn.

Slim tells George that Curley is still mad about his hand and will try to kill Lennie even if they bring him in and have him locked up.  When Curley reenters the barn, George begs him to not shoot Lennie.

'Dont shoot 'im?' Curley cried. 'He got Carlson's Luger. 'Course we'll shoot 'im.'

In an effort to distract Curley from his purpose, Slim says, "'Curley--maybe you better stay her with your wife.'"  Curley reddens, knowing what the others think.  Still, he replies,

'I'm goin'....I'm gonna shoot the guts outa that big bastard myself, even if I only got one hand.  I'm gonna get 'im.

Clearly, it is evident that Curley's desire to avenge himself against Lennie who injured his hand and to satisfy his egotistical desires is dominant in his mind. Lennie, again, is the victim of his mentally disabled nature despite his conditioning by George.