I'm wondering if once they get together Mok will drop the Nanjo-ssi way he calls him... Nanjo didn't seem happy about the hyung name and for some reason I can't really see Mok using it constantly, maybe just sometimes to tease Nanjo. It would be really cute if Mok called him yeobo/jagiya and Nanjo switched to Mokyeon-ah
I'm happy to finally see more Katya scenes, I know a lot of people hate her but she's a great and complex character