Thank you! I'm glad I was helpful. I think he just trusted the staff to inform him if anything happened to them but, because of society's standards regarding illegitimate children, they didn't. Now, they are more than likely going to pay for it.
He probably expected them to at least be living comfortably.
https://newtoki65.com/webtoon/2213307/쌍둥이-남매의-뉴라이프?toon=일반웹툰
Little bit of advice.
I have found that when the work is first posted that someone will post raw links in the first 50 comments or so. Enjoy!ヾ(❀╹◡╹)ノ~
I mentioned this before, but the reasons for their father ignoring them are based on the time period. When a royal has illegitimate children, their lives are already forfeit by societies standard in the social circles. In the actual world, they would be walking around with targets on their backs. They dont have guardians or manifestations to prove their "worth" in society's eyes.
If the king showed ANY kind of affection for them before (the names were already pushing it) then they could be used as a weakness and be considered a target as they dont have the abilities the rest of their family does.
Spoiler
We also see evidence of this in ch 24 when the first assassination attempt is made on them