Here is my hot take:
Cheol had his doubts about having a relationship with a man, Ji made it clear that he forced him to have sex the first time they did it. Also, Ji outed him to his dad, Cheol ran away and Ji did not followed after. They blame each other for how they ended up being apart, but this last arc made it clear that Ji is doing everything so that Cheol is completely dependent on him
he definitely was traumatised by the outting to his dad especially because his dad clearly never really cared for him, revealing something like that on his own without warning was for sure a big betrayal in cheols eyes, i mean he literally ran away from home to live in that study room because of that incident. it also seems like ji never actually apologised for it either based on the fact cheol still wanted to hear an apology from him?
ji 100% did cheol wrong imo but i don't even hold it against him because he's insane and cheol's dad was a dirtbag anyway plus cheol still loves ji regardless of his hurt feelings
Basically what we know so far is, like people have said, though we know it definitely did happen, ji outed cheol to his abusive dad and then never apologised or anything, forcing cheol to run away from home because he was scared the dad would kill him. Ji then went crazy because he thought cheol had abandoned him and was gonna kill him but then, after realising how much cheol did acc like him after he said his name while sleeping, he decided to focus his attention on protecting cheol and getting rid of all the obstacles to them being together. Which involved him going away for like 10 years and getting rich and powerful so he could come back and help him out

So Cheols trauma is his actual father that made him 'homophobic' after finding out he dated a boy and he married a woman and they broke up because the woman was falling out of love but I do NOT get why Cheol is traumatized by Ji, is this some kind of cope that he acts insane because he didn't want his ex to appear in his life again? AND WHAT DID JI SAID TO CHEOL IN HIGH SCHOOL THAT MADE THEM BROKE UP?? We need detectives here
Also is this an toxic bl or just average cause im genuinely confused..