What favor does George ask of Candy?

George asks Candy not to tell the boys that he'd seen Curley's wife's body.

Now you listen. The guys might think I was in on it. I’m gonna go in the bunk house. Then in a minute you come out and tell the guys about her, and I’ll come along and make like I never seen her. Will you do that? So the guys won’t think I was in on it?”