Curley's wife stands at the door and starts harassing Crooks with mean remarks all because he is black. Crooks tries to defend himself. Curley's wife puts Crooks in his place. Crooks seems to get smaller and smaller as she keeps saying rude remarks.
Curley's wife let Lennie pet her hair and when she told him to stop he gripped her hair and would let go. She kept telling him to let go. Curley's wife was struggling to get out of Lennie's grip. She didn't have enough strength to stop him. Lennie held all power over her. She was powerless compared to him. She was terrified.
George is talking to Lennie about their place they "were" going to get. George gives up on him and shoots him. George tries to make Lennie happy before he shoots him. He doesn't want Lennie to die in pain. George never wanted to hurt Lennie but he had no choice. He didn't want anyone else to hurt him other than himself.