What's wrong with Dmitry? Why is he so determined to get rid of Leewon??

I think its because he made caesar act differently and taking attention but idk

I think he has like a sibling complex almost with him so he doesn't like Caesars attention on SM else, not that they R siblings tho lol

I think it was said that they were cousins and childhood friends earlier in the chapters, but can't remember which chapter

they are cousins yh, they grew up as children together pretty sure