That's why I waited until I finish reading the novel to give any comments on the manhwa. Manhwa authors always remove the most important part for ML, changing the entire dynamics of the plot. It's always the case. If manhwa is based on a novel I will always, without a doubt, recommend people to read the novel first before jumping to any comments
That's actually my practice too, i read the novel first because i know adaptation conditions will definitely alter both the plot and character dynaminc so i could compare later on what changed and gut cut. I would even defend or leave a detailed reviews of the novel if the manwha didn't do it justice (ahem Payback)

I gotta spoil because I can’t let people misunderstand our ml who is a green flag and patient like no other, the author really added this scene for no reason because it doesn’t make sense for the characters but whatever, so I have to defend ml a bit spoiler :
: in the novel he drank all the alcohol he found at the house in front of mc to show him why alcohol is bad he didn’t plan to do this at all, the problem is that he drank one of the bottle seowoon (mc) received as gift earlier from the original mc of the novel (forgot his name) in which there were drugs inside (that makes one not themselves : violent, acting on desires,… ) because you know original mc always has creeps around so the alcohol was drugged and ml drank it,
Moreover as it is shown ml really regrets what happened and refuses mc refusal to see it as rape he considers what he did rape and until this issue is addressed no sex
He really is a green flag I love him and I hate that the author added this scene
Voila