Aloof King and Cool-Acting Queen by Kasumi Ritsu also known as 冷徹王とクール(仮)な王妃 by 霞律
Novel Updates Page (with links to where you can read the other chapters): https://www.novelupdates.com/series/aloof-king-and-cool-acting-queen/
The queen’s essential feature is this: [must be a woman or a feminine-looking man].
——- “No, no! That’s no good at all!”
This is the story of an unfortunate young man who tripped into a different world and had to become the Queen of the largest country in that world.
“Being held by a man is no joke!”
Thinking it’s impossible for him, he decides to act as someone with a cool personality!
*denotes chapters with NSFW content