In "This Is What It Means to Say Phoenix, Arizona," Victor knows that he will not be friends with Thomas when they return to the reservation because the forces of peer pressure and habit are too strong for him to resist.
Victor and Thomas were once friends, but Victor became antagonistic toward Thomas when they were teenagers and beat him savagely for no reason when they were both fifteen. Over the course of their journey to Phoenix, they appear to become friends again, but when they return to the reservation, it is clear that this new relationship will not last:
Victor knew that Thomas would remain the crazy storyteller who talked to dogs and cars, who listened to the wind and pine trees. Victor knew that he couldn't really be friends with Thomas, even after all that had happened. It was cruel but it was real.
Thomas understands this and accepts it. He knows that Victor would lose his other friends if he were to try to be kinder to Thomas. Victor's hostility to Thomas has ossified into habit. All Thomas asks is that Victor stops and listens to one of his stories someday. This is the nearest the two men can come to friendship.