He says that Lennie is childlike, and that he is not mean at all. He means no harm.
George tells Lennie to fight back and defend himself if Curley hits him. George wants Lennie to stand up for himself and not allow others to take advantage of him.
George feels that it is his responsibility to care for Lennie because he couldn't survive by himself, but he also feels like Lennie is holding him back.
George doesn't help Lennie in the fight because he knows that Lennie is strong and can handle himself. George also wants Lennie to learn to stand up for himself and not rely on George for everything. Additionally, stepping in may escalate the situation and make things worse.
The boss suspects that George is taking advantage of Lennie by making decisions for him and speaking on his behalf. He questions the nature of their relationship and whether George is exploiting Lennie in some way.
Crooks begins to tease Lennie, in that he begins to upset him by telling him that George might not come back. This upsets Lennie because George is the only person he has, and also Lennie feels secure with George by his side. Crooks also teases Lennie due to the racism evident in society during that period. Lennie presents himself as a vulnerable character before Crooks and so he pounces at the opportunity to upset someone else.
The boss suspects that George is trying to take advantage of Lennie by speaking for him and making decisions for him, rather than letting Lennie speak for himself. This leads the boss to question George's motives and the nature of their relationship.
He remembers to wait for George
GEORGE killed LENNIE because Curley was going to find him and shoot him anyway. George wanted Lennie's last few moments to be happy, so he decided to do it himself and tell him a story beforehand.
Well at first he tells him to stay away from him, but when he starts to get punched by him he says to fight him.Two things that George tells Lennie to do with regards to Curley are to "keep his distance" and "stick up for himself".
The boss was suspicious because he thought George was trying to cover up for Lennie's lack of intelligence or understanding. He may have also questioned George's control over Lennie and their relationship dynamic.
Crooks tells Lennie that if George doesn't return, Lennie will be sent to an asylum or locked up because he is too "dumb" to take care of himself.
The boss assumes that George is taking care of Lennie because Lennie is not capable of taking care of himself due to his mental disability. He may also assume that George is taking advantage of Lennie in some way by having him work with him.