In Faulkner's "Barn Burning," Sarty, the boy, feels that these new employers are beyond his father's reach. He feels relief, and for a moment actually forgets completely about his father, which, apparently, is rare. Abner, Sarty thinks, is only a wasp to the De Spains, capable of stinging a little, but incapable of any real harm.
This temporarily relieves the pressure Sarty feels from his internal and external conflicts. He is being told by his father, on the one hand, that blood relatives come before everything else. But his conscience tells him what Abner does (burn barns) is wrong.
The tension of the conflict is between what Sarty is ordered to do, his family, and the wrong that Abner does. Sarty is temporarily relieved of that tension when he first sees the de Spain home.