hmmm

Let me help
Main character name is daon and he likes jaemin (the blondie who tutor him) but jaemin like soohyun (the dimple domestic violence piece of trash) and soohyun like daon

But soohyun dated jaemin before (despite soohyun not liking jaemin) and it didnt end well for jaemin so his (nonexistent) heart is hurt and daon feels bad for him because he is seeing someone he love sad. So he trying to make sure soohyun never hurt jaemin again. (Btw jaemin still like soohyun till now)

The ml name is seonghyun and he like daon (duh) and daon start to develop feeling for seonghyun but still in denial.

The case now is
Soohyun is back in town and threatened daon that he gonna get back with jaemin just to hurt jaemin again if daon didnt compile to his wish which is basically force daon to act like soohyun's boyfriend

ahh this actually made it so much easier to understand, thank u so much for the explanation !!! soohyun go fuk urself already tho lolol