I laughed when I read the title, and laughed even more as I read. Not only does it have a cute aspect to it, but people who are grieving and learning to love in their own way. And the definition of a demon/monster isnt what's usually thought of it's by how you treat others--since you learn that the demons are being mistreated at times and the demon lord defends all those under his command--him learning to be a father as well as the protagonist learning to be a mother to magically conceived children is quite amazing.
I Became the Mother of the Strongest Demon Lord's 10 Children in Another World.