So this is way late but- apparently the Duke was the DEMON KING'S son and the mother was originally human... it was a plot to put the demon king's son in the human royal family. Since the demon king turned the human mom into a demon (resulting in her early demise, her human body unable to withstand being made demon), everyone assumed being half demon came from the mom and the king was his dad, which wasn't really the case. Therefore, regardless of Alexa's royal lineage, the Grand Duke Bel never shared blood with the royal family.
You are right in the sense that he's still *technically* an uncle on the family tree and no one knows they're not blood related... but royalty married in their own family all the time back in the day, which is actually why royalty in the middle ages had a lot of genetic issues and illnesses. Marrying your half-brother's daughter isn't genetically much different than marrying cousins. The genetic issues with that usually aren't too bad, it's just when cousins keep interbreeding that genetics become an issue (which again, yeah, royalty used to do it all the time when humanity didn't have Darwin spittin facts).
Only the readers/audience actually care about the love interest being related in some way. The people in the story probably wouldn't care at all.
So he was never really the previous king’s son. That’s actually a good way to untangle the “incest” issue while still using it as a plot. Did the mom and previous king actually had a relationship whilst being pregnant with the duke? Thank you for answering btw.
No probs. Honestly, I'm guessing she must have slept with the human king very early in the pregnancy, since the human king assumed Bel was his son. There's so many tiny plot holes though, like, if she was a human when she had Bel and was then turned demon, why did the human king assume Bel was half demon because of the mom? Did he think she was pretending to be human and later exposed herself as a demon...? If Bel was half demon coming from a human mom, the king should've known Bel wasn't his UNLESS the human king thought she was hiding her demon self.
If the demon king was in love with the human mom, how was he okay getting her pregnant and then just passing her off to sleep with a human king for a while?? Then took her back, leaving the baby behind as the human king's fake son, and turned her into a demon supposedly out of love? (Though turning her demon sounds more like just camouflaging where Bel's demon blood came from.) That just doesn't feel genuine to me. To me, it sounds more like the demon king treated her like some kind of possession to use.
The whole thing was pretty terribly explained. This was based off a novel, though, so I'm assuming the details were better explained in that version. This adaption made the bloodlines seem so awkward and tangled.
Before reading this again, was it ever addressed how the ml is technically the fl’s uncle?? Because it was mentioned that the ML is the previous king's son with a devil and the current king is also the previous king's son so he's technically the female lead's step uncle