Netori: Stealing The Hero's Party! - Chapter 12: Helping To Lounge

Diablo Volfir, a mighty magician, was sealed for aeons due to the schemes of the 12 Gods, but 66666 years have passed since then, and he descends to earth once again!

The dark underground dungeon was filled with countless ancient relics and treasures. Eerie, deformed, cursed objects... The abyss, catacombs, Ancient Gods, mythical races... Mechanics, cursed seal implants, and the gargantuan black towers... A peculiar mix of Alchemy, a drop of steampunk, two spoons of supernatural mystery, blending into a vibrant and colorful fantasy world. I am a puppeteer Alchemist. All that my eyes behold, becomes my puppet. Alone, I am an army!

She is the slow-witted idiot of the Prime Minister’s Residence. Everyone bullies her. He is the most respected and unfeeling Prince, with frightening ability and absolute envy! Together, they are conferred an imperial edict of marriage.

She acts stupid and tries to decline in every way possible while he despotically escorts her into the wedding…… everyone ridicules the match, but no one knows that the “idiot” has transformed from a loser into a talent.

After the marriage, when they encounter the Empress Dowager examining the room, they act in concert with each other and pretend to be two mandarin ducks deeply in love. Afterwards, she laughs, “The performance has ended. Your highness, please return.”

He laughs softly, “Since you’ve got onto this Prince’s bed, don’t even think of getting off.”

- Description from Novelupdates

My reunion with her took place in the worst possible way.