Not to the point of being beyond repair? The guy literally tricked and forced Jae-in into having an abortion. Nah, that ain’t forgivable.
That's why I am saying probably if they communicated, they could have salvaged whatever relationship that have left between them. It doesn't necessarily have to be full of enmity. I pity Jong Hyuk in some way because his upbringing shaped him into some kind of twisted man. He doesn't really know how to love properly. Never had anyone around him that genuinely cares about him. Right from the start he was always trying to survive. That's why his love is so destructive and seems more like obsession. It's a fact that he gains power not because he wants it for himself to live lavishly. He wants it so that he could love Jae In freely, without any interference. He mirrors ML. While both of them doesn't grow up with proper upbringing, but ML still had that sane period where he receives love from his parent. That's why he turns out well.
I always think, if they both talked properly about the baby, and he find a way to shield Jae In from his father in a less extreme way, it could have been a different outcome because clearly they both used to love each other. I also think he feels somewhat guilty for what he does to Jae In, and that's why he lets Jae In do what he wants. Alas the choice we made will always come back at us, in one way or another.
If they have like spinoff for Jong Hyuk I would definitely read it.
Feel like the story could have been better with the common power dynamic shift on the relationship lies on the omega.
Honestly I think if Jae In and Jong Hyuk communicated well their relationship doesn't need to be a tragedy. The relationship could still be saved to a certain extent. Not to the point where it is beyond repair. But I understand because the story is not about jong hyuk and jae in.