Long story short
The Duke is a Hybrid Dragon with both genitals
The Dr. Told him his female womb is detorating and leading him to become infertile.
Since he has a womb & no balls which means he has no sperm so he can't get anyone pregnant.
So if he wants to have kids to live out his legacy he best bet it to become pregnant now before he's infertile.
The problem is the Duke is way too powerful and his body rejects/blocks any sperm that isn't powerful as him or higher.
The only person as of now that meets the Dragon power is the emperor. The emperor power is just as great if not greater then the Duke. So he has a higher chance of becoming pregnant if he sleeps w/emperor.
He refused to sleep with the emperor at first because he knows that the emperor is not only in love with him. But would want to raise their kids in the palace. The Duke doesn't want that he wants freedom for him and his kids.
This is also a harem story so the Duke is pretty much polygamous so he sleeps with whomever and whatever
Hopefully that helps.
uh..idk why im reading this... i understand nothing at all..