In Chapter 4 of Roll of Thunder, Hear My Cry, why does Stacey decide to tell Mama what happened at the Wallaces' store?
Stacey finds himself in hot water because of decisions he has made and his friendship with T.J. A guilty conscience hounds Stacey into refusing to use a cheat sheet on his test, but when he is handed a copy by T.J. and is then caught by the teacher, Stacey takes full responsibility. He is whipped while T.J. remains silent. Later, Stacey breaks the steadfast family rule about visiting the Wallaces' store; he knows T.J. is hiding there. As the two boys fight, Mr. Morrison suddenly appears and "lifted a still-swinging Stacey off T.J." Later, as the children worry about the whipping they are likely to receive from Mama, Mr. Morrison surprises them when he softly tells Stacey that "I ain't gonna tell her." Stacey realizes that this is a way out. He has not been bloodied, so he knows that if he can
... just figure out a way to explain the bruises on his hand to Mama without lying he was in the clear. (Chapter 4)
But Mr. Morrison has a condition: "I'm leavin' it up to you to tell her." Stacey does not say why, but he decides to tell Mama the truth. Unlike some of his immature decisions made earlier in the day, Stacey seems to take a step toward manhood when he decides to tell Mama about the visit to the Wallaces' store. It is a bonding experience with Mr. Morrison--"the two of them smiled in subtle understanding, the distance between them fading." Stacey manfully takes responsibility without lying or admitting that the other children were present, leaving Cassie to wonder about "How we had managed to escape a whipping we couldn't fathom..."