Moo why u be cheatin on my boy?

He's just putting Joohyuk in his goddamn place, haha
They still have a consensual fake relationship right now, so technically it's not cheating and they can do what they want with whom they want (even tho Moo is crazy protective, lol. He didn't lie when he said he's super into Kirin)

Coz joohyuk is so obsessed with kang mu... but kang mu likes kirin

Kangmoo doesn't like Kirin.
Oh, of course, it is true that he like it in a different way. ╮(￣▽￣)╭