Actually, I found this story pretty sad. The duke really loves Elle, and in the first chapter with the other omega getting pregnant it's tough for both of them. But the author went crazy with Elle's return to the past, he had already become an omega (Elle), so there was no need for him to betray the Duke. There is a lot of discrepancy between the first chapter which is darker and the last ones which are just obscenity. I feel sad for the Duke, for the knight and for the baby.
The alpha's father chasing the omega doesn't make sense. This to me seems like an overreaction and motivated by nothing. I hope this manga gives good reasons why this crazy dad is doing what he is and good explanations for why no one ever reported him to the police. It's already bordering on absurdity!
I'm at loss for words, this is only smut with a really bad story.