Curley, Slim, and Carlson are returning back to the barn after Curley tried to through a scare into Slim but was the one that got scared. Curley had thought that his wife might've been with Slim.
George and Lennie are scared that they would get canned
I don't know
Will we get canned now?
After returning back they were talking, Lennie giggled a little and Curley believed he was laughing at him. This angers Curley and he starts a fight with Lennie. Everyone else tells Lennie to hit back or to tell Curley to stop.
Slim blackmails Curley
If you tell the truth, we will tell what happened
After George tells Lennie to get him Lennie catches his hand and starts to break it. Everyone has to punch Lennie and shout at him so that he would stop.
George ensures Lennie that it will be ok
Don't worry Lennie it wasn't your fault
I didn't want to, but you told me to
After Lennie broke Curley's hand they get scared that they would get canned. They ask Slim in fear but Slim doesn't know how it will turn out.
I didn't want to!
Slim wants to make sure that Lennie and George don't get canned. Slim does this by telling Curley that they would tell what actually happened to hear if George and Lennie get canned. Curley doesn't want that to happen so he agrees
Lennie starts to get nervous and tells George that he didn't want to do it and is scared that he wouldn't be able to tend the rabbits. George tells Lennie that he could tend the rabbits and that they wouldn't get in any trouble. This is to comfort Lennie.