In this scene shows how George has integrity to do what he says and is a man of his word. He is asked by the boss why he doesn't just leave Lennie, he says that he sticks with Lennie because he promised Aunt Clara he'd take care of Lennie.
The theme here is loneliness, it can relate to Curly's wife as she can't talk to anyone but Curly. “'I get lonely' she said 'You can talk to people, but I can't talk to nobody but Curley, else he gets mad. How'd you like not to talk to nobody? '” (87)
Metaphor:She's a rat trap if I've ever seen one.(32)