I'm gonna give this a chance because it was the same author as Define The Relationship but...

I know, I’m so scared. There is so much green flag, healthy relationship activity in Define the Relationship, which really puts it above the current standard, but this one has a darker theme and it usually doesn’t end well ┗( T﹏T )┛

Glad people are agreeing with me... Usually people don't like my take on toxic relationships.
But yeah I get it, I'm pretty scared too which is why I don't plan on putting my energy into this manhwa if it goes down the wrong path.

same. im getting weird vibes but maybe it’s good
im also unclear who the relationship is going to be centered around

it’s cant be the blonde guy nahh this is gonna be odd
arent they brothers?? or is translation weird
i know they use different honorifics in korea but i cant tell if they’re actually related</3

I just re-read it because I wasn't sure either. But I do think it's bark haired Mafia dude x ballerina blonde dude. And yes the dark haired one does say "younger brother" but I think it's missed translated, I think it was supposed to say something like "*name noona* witch is what older males call younger males. If you go back to re-read it the translator does add notes beneath that part and they do say something regarding that fact.

It's obviously the blond with the mc

Noona is for women

Damnit haha sorry I tired