in the final scene how come goerge does not scold lennie? why does he tell him the dream again? why does he shot him?

George doesn't scold Lennie because the ending has already been decided, and George knows that it had always been to much to ask for anyway. He asks Lennie to tell him the dream in order to distract him........ he shoots him because he doesn't want Curly to get to him first. Geirge ends it quickly because he loves him.