Darl uses hyperbole in Chapter 52 to express his distant relationship with Jewel:
“Here,” I say. “He dont mean anything, mister. Jewel,” I say. When I touch him he swings at the man. I grasp his arm; we struggle. Jewel has never looked at me. He is trying to free his arm.
At this moment in the novel, Darl is restraining Jewel from getting into a fight with a stranger who remarked upon the stench of Addie’s corpse. Keeping Jewel out of harm's way—no matter Darl's personal distaste for him—is part of Darl’s brotherly obligation to Jewel. Their relationship is so strained, though, that Darl remarks, “Jewel has never looked a me.”
This is certainly an exaggerated statement, but it demonstrates Darl’s that he and Jewel do not have a close relationship and that this pains Darl, who sees this estrangement as Jewel’s decision. Using the exaggeration "never" here reflects the intensity of Darl's pain. He feels deeply rejected by Jewel but sees their estrangement as existential. Since they have "never" been close and Jewel has "never" looked at him, it seems like a resolution between the two is impossible. To Darl, they are naturally opposed and have no hope of reconciliation.