Dowon (artist) and Dojin (lawyer) are brothers. Dowon asked Dojin to represent Beom in his legal struggle against that guy who was financially (and physically) abusing him.
Dowon had a crush on Taeju during high school. Dojin has had a major crush on Taeju all his life.
Dowon knows Dojin is dating someone but doesn't know who. Beom and Taeju only know they're brothers, but they have no idea about each brother's SO.
Why is Dojin jealous? No idea. After all, Dowon was rejected by Taeju and he is deeply in love with Beom. I think it's just his possessiveness and desire to keep his life private.
guys i am so confused tell me if i'm wrong but so are dojin and dowon brothers and taeju is married to dojin? how would dojin even know that dowon's dating beom and is that why he's mad? because he doesn't want taeju to know beom because dowon is dating him and dowon's dojin's brother and they don't like each other??? please help me understand this i'm so lost