
I think there's already spoiler below this topic. This is my version:
So white haired guy has plans to take over MC's father business. Somehow MC and ML getting closer is in the way of his plan (I'm not sure yet how besides that he's planning to get married to ML's sister but I feel like there's more to it). He told MC to leave ML, he expected obedience from MC. So when MC didn't do as he say he drugged MC and raped him. Before that he also showed MC with pictures of MC and ML kissing saying it'd ruin ML if exposed. he lied that it's from reporter and he helped MC settled it (the truth is he was the one paying for someone to take those pictures to blackmail MC). These drove MC to isolate himself from the world especially from ML.
Big Daddy white hair is gonna be a problem...on some "i kept u waiting forever but now im involved when i see ur moving on" type shit