How we cite our quotes:
The most traumatic events ever to befall the longtime front man of the Traumatics had been (1) receiving a Grammy nomination, (2) hearing his music played on National Public Radio, and (3) deducing, from December sales figures, that Nameless Lake had made the perfect little Christmas gift to leave beneath tastefully trimmed trees in several hundred thousand NPR-listening households. The Grammy nomination had been a particularly disorienting embarrassment. (3.1.2)
Richard sees his mainstream success as a betrayal of himself and his values. It's noteworthy that he describes it through the prism of being the "longtime front man of the Traumatics." This seems to suggest that he's actually betraying some younger version of himself, and concerned he might have compromised his ideals somewhere along the way.
The angry stirring of Katz's blood was of a piece with the divinations of his dick. I'm going to do you a different kind of favor now, old friend, he thought. We're going to finish some unfinished business, and you and the girl will thank me for it. (3.1.406)
Betrayal! Richard seeks to once again seduce Patty and destroy her marriage, and he's committed to this (um, terrible) plan both emotionally and sexually. But of course Richard insists that this is another example of his devoted loyalty. Can it be both?
"And I totally abandoned her, because Dad hated her so much. She was suffering, and I never called her again, and I threw her letters away without opening them." (3.2.173)
What most obviously follows betrayal? Guilt. Decades later, Patty cannot have forgotten that it was Eliza who lied and deceived her. Nevertheless, she feels guilty for not forgiving her, and this now feels like a betrayal. Perhaps it's because Patty has had so few meaningful relationships in her life. But notice how she prefaces this remark by blaming Walter – "It's Walter's fault that I betrayed her!" Maybe she's just looking for yet another reason to feel bad.