
WE have the same thought. I love reading yours. I mean i keep zooming the panel and the MOLE is on the right while the ML's should be on the left. So there's really a big misunderstanding here. And the MC thought the ML is just playing with his feelings that why he put boundaries.. while the ML is taking his "revenge" with the MC because he thought that jhe left him

Sorry but I have to disagree with your theory cause the seme doesn’t have a twin bro but he does have an adopted step bro and there’s no way the mc would mistake the bro for the seme cause they might not look alike (not twins). I agree with the others that the step bro might have gotten jealous cause his bro liked the uke and tried to blackmail him which eventually led to the kiss.

Well, check the flashback panel where MC sees « ML » kiss someone else. He doesn’t have ML’s moles, but he’s got the same as the stepbro. I personally can not find any good reason for ML to put on make up to mask his moles and put his step bro’s, while not wearing any wig to match his hair.
Them looking alike with a wig is weird, I agree, but it’s either poor writing or a twist about blood relationships ╮( ̄▽ ̄)╭

Honestly, I was shocked everyone said it was the brother he kissed because the hair color was different to me.
However, it's already been established in the story that they are not blood brothers, so not his twin. Maybe either one of Seo-in's parents had a child each and then got married or something, so they became siblings.
Oooh ok I understood! So back when they where highschoolers, there WERE a bit something between them, thought they each hid it behind a « we’re just making out for fun lol ». As they each grew feelings, MC sees ML kissing someone in the class and gets heartbroken. BUT we can see on the kissing panel the moles are not the right ones, it’s ML’s twin! Who is wearing a wig apparently cause that’s not his hair color.
So then we get MC who thinks that the « we’re just making out for fun lol » was indeed for fun and no flirting, and he breaks things up with ML. Things happen, ML’s twin dies, years pass, and MC and ML met again. They both are « oh, my old crush who broke my heart by being interested in someone else/breaking up out of nowhere! I might have a chance this time! ».
But they are both idiots who won’t talk about « hey last time when we were in high school you did this I was sad. I had a crush on you it’s a bit embarrassing but YEARS HAVE PASSED SO I CAN TALK ABOUT IT ». So instead they feel anxious around each other and play a game of tag. So yeah, now I understand why ML thinks MC is weird with his boundaries.
Only mystery left is why the brother wore a wig and why he died. Was he jealous of ML and trying to pass as him to destroy his reputation?