Why did you read it? It had warnings I think?
its not about being sensitive towards it, it just seems very unnecessary to the story. the author could've put it in a vague sense that readers could understand he was sexually abuse by his father, but putting a whole sex scene is just a bit too umm. In most mangas/manhwa, child sexual abuse is rarely illustrated in detail so its also sortve taboo to explicitly have it drawn (feels like im looking at cp)
I think it was intentional, to be shocking and real put that sort of heartbreaking visceral trauma. Same thing happened to me when I read “Killing Stalking”… (couldn’t believe people love something like that). It’s an unfortunate reality, especially hard to deal with even if it’s fictional.
5th chapter didnt need to be that graphic about past life of mc, that is literally cp