George explains to Slim how Lennie followed his instructions and trusted him every time and how he teased Lennie that he was “too dumb even to know he had a joke played on him.” Which gave him fun. The teasing came to an end when Lennie trusted George and agrees to jump in the river, where he almost drowned, “He near drowned before we could get him. An’ he was so nice to me for pulling him out. Clean forgot I told him to jump in.”, realizing how much power he had over Lennie and resolve to never tease him over his trust.