In Chapters 21 - 25, what kind of relationship do Orin and Hal have?

Hal and Orin have a strained relationship in Chapters 21 - 25. They talk, and it is clear that they do not have hard feelings for the other, but they are not entirely comfortable. They are unable to discuss family matters, for example. Orin has questions for Hal about the separatist movement in Quebec, but Hal does not find interest in anything Orin has to say. It seems that Hal especially dislikes talking on the phone when he is using drugs.