It gets to the point where he hates hearing their voices, both so full of false cheer, like maybe 15 years in maximum security and a swastika burned into your ass by a neo-nazi isn't so bad. He hates that it's getting harder and harder to reply to his mother with anything more than one-syllable responses and stagnant clichés. And he's not sure whether to loathe or love the fact that he spends these calls counting down the minutes until the money on his card will run out and he can get back to Chris again.