Responses
I think your talking about He Guanyu & Xu Xingchen on chapter 23 they had twins and the bottom is the sibling of Mr he (their story is technically a continuation as they are the side couple)
https://zinchangmanga.net/manga/he-guanyu-xu-xingchen/chapter-23/
Where the mom is a male Alpha and the father is a male Beta. They have twins but they're ugly newborns but when they grow up they're handsome.
I looked everywhere for it and couldn't find it. They said is called Mr. He, but the only Mr. He I found was Shounen Ai and it wasn't Omegaverse.
If you could help me I'll be grateful, thanks.