"Not sure exactly what the point of that is."
"Just that I'm still committed to my family."
"Good. It's a great family."
"Right, so I'll see you in the morning."
"Patty." He put out his cigarette in the commemorative Danish Christmas bowl of Dorothy's that he was using as an ashtray. "I'm not going to be the person who wrecks my best friend's marriage."
"No! God! Of course not!" She was nearly weeping with disappointment. (2.3.363)
All things considered, Richard is pretty loyal to Walter. He tries – he really tries! – to be a good friend. When he finally betrays him, it's through his convoluted logic that it's for Walter's own good.