ik this is a joke but swearing is incredibly common in young Korean men Also it could be a translation error, also also some authors use it as a way to show a characters social/economic class or how well they do in school or to revert stereotypes. He is a very sensitive artist who makes good grades and has loving parents but still cusses in ever sentence, so I think it could just be a reverting of a common Korean stereotype!

I wonder what mls favorite word is cause he's talking like a vivziepop character