It’s omegaverse with mpreg. Seme is alpha but not sure if uke is an omega or beta. They were locked in a room and can’t leave unless they have sex, which they did. Uke found out later that he’s pregnant…? Seme has black hair and possibly has a twin. Uke is blonde.
Not sure if this manhwa was ever translated and uploaded to mangago. If it’s not, just the title in Korean is fine too. Thank you!
And the academy award for the best actress goes to…the empress!