Maou-sama no Haramase Douchuuki

"To seed wombs with the heir to his evil empire, THE DEMON KING CUMS!"

By counsel of his trusted maid Millhiarya, and as his imperial duty as the Dark Lord who ruled over this continent, it was time for him to bear a Son... The Dark Lord thought long and hard. He deemed it necessary to travel outside the castle, to tour the wombs of the land for the one deserving of his hellish offspring. The journey began. But there were unseen perils lurking in the land.

(Source: DLSITE)