And now the twist is that they're not actually blood related. Or so he says. He kills the other men who were his competition but somehow his story feels like it doesn't add up.
I guess a possible sequence is this:
Duran marries Miranda -> He is kicked out by her family -> She gets pregnant -> He returns to burn everything down
What's unclear to me is when he actually married her, he calls her his wife... but at the same time says he and other men were all just marriage candidates. Don't tell me that was some "NTR as a background story" with him as the man who came back to destroy everything for his revenge.
I don't think we'll ever get her mother's side of the story, but now that we know she's a princess I think it's highly likely she was forced into such an arrangement by her family.