(1) To me, this situation was just like when a human guardian rapes the child they're supposed to take care of.
(2) This story is tagged as "sexual violence" which usually implies non-con situations and/or sexual abuse
(3) The author wasn't really trying to make this scene into another "hot non-con bl" thing -- Hayoon didn't give consent or have an erection, wasn't "into it" and even had a monologue on how he got into this terrible situation
(4) So no -- I don't think Hayoon believes this is normal, but has become accustomed to abuse, similar to how a lot of victims of child rape grow up (e.g having the mentality that rape is acceptable)
So if you drop this, drop this because you're not comfortable with sexual abuse...not because this may be another author trying to pass off rape as normal.
Thank u for another (albeit sad 😥) chapter♡♡