Ponyboy first gets upset with Cherry in Chapter 8 when she says that she will not go visit Johnny at the hospital. He feels like "It was the least she could do. It was her boyfriend who caused it all" (128). Ponyboy's rudeness stems from an anger that runs much deeper than just Cherry's refusal to visit Johnny. He is really just upset about everything that has happened, and he lashes out at Cherry because she is a Soc and a convenient target, like when he says:
"Do you think your spying for us makes up for the fact that you're sitting there in a Corvette while my brother drops out of school to get a job?" (129)
Ponyboy realizes the rudeness of his behavior as soon as he looks back and sees Cherry's face. He felt "ashamed...She wasn't crying, but she was close to it" (129) With this realization and Cherry's confession that she was just trying to help, Ponyboy makes amends with Cherry Valance.