Arthur will feel the conflicted feelings inside of John, some seemingly discordant notes that nonetheless make a coherent melody. Some wounds did not get addressed back when they had their tiff, and John's kept it to himself because Edwin and Arthur had had their own difficulties. But now that he's airing it-

"...I'm still kind of pissed at him. About how things went a while ago. Not-" ugh "not as much the big thing. The fact that he didn't trust me enough to talk to me. Again." There's a low rumble. "It's not technically related, it just..."

Edwin took something that made him so happy, a connection with Charlie, trust and building something with someone, and made it something that almost broke him. Edwin yelled at him about 'choosing' and got upset about it and then there was a big party about him being chosen.

He wants to be happy for him, is happy for him, but he can't get rid of the petty little part of him that-

"...makes it harder."

He knows he's being a sullen teenager about this, that he should be better, that he has to be better. It's just not happening. And if he's going to be ugly and stupid and small, he knows he can be that with with Arthur.

Arthur might yell at him, but he'll still be there.