Ok so I have the feeling that the ml traveled back in time, that is why he knows alot and that is why his reactions are like that. We see a timeline where he tries to fix things and mistakes. I also read a theory mby a spoiler similar to this somewhere, but again, just my thoughts.
Even tho I feel sorry for In-seob, his character (the way it is written) is really starting to pi** me off. I have read so many BL mangas and somehow the main character is always incapable of standing up for himself, it's the classic. But in this story it is going too far and too long. I mean this guy doesn't even cuss or say a word against that ass****😕 Feels like the plot is not moving foward.