Maou na Ore to Fushihime no Yubiwa - Volume 4 Chapter 4 — Onsen!

The prettiest girl in the class, the campus belle queen, an attractive policewoman, a cunning reporter, a charming businesswoman, a mesmerizing commando, and a millionaire spendthrift, all shall lose themselves to passion.

Be it a Lolita, a virtuous woman, a regal queen, a mature racy woman, a cold-blooded goddess, or a sexy baby-faced doll, all beauties shall come to his embrace.

Young and inexperienced, equipped with the [Flower Pickup System], young schoolboy Su Ke, felt his life become more and more chaotic…

- Description from Novelupdates

After she had transmigrated into the body of an abandoned wife of a little marquis in Ancient China, Su Nuan Nuan, a modern-day food lover was delighted!

Summary 1) Tang Yuan suffered from a strange illness, so because of this, Tang Yuan pounced upon Xie Yu. A month later, Tang Yuan discovered that Xie Yu was a big shot in the world of tianshi (Taoist Masters), his existence the greatest fear of numerous ghosts. But that big shot was now obligated to marry him, because he was carrying the big shot’s steamed bun.

One year later:
Xie Yu: “Isn’t it time for our pup to be born?”
Two years later:
Xie Yu: “Don’t worry about it. Maybe you’re carrying a nezha (protection deity who was carried for 3.5 years in mother’s womb)?”
Three years later:
Xie Yu: “You really are probably carrying a nezha!”
Ten Years later:
Xie Yu: “Shall we not just give birth to this child? Since he’s obviously not ready, let’s beat him up!”
Pup: “I will remember this animosity for the rest of my life!”

After being carried for ten years and one month, the steamed bun was finally born. The steamed bun was white and tender at birth, extremely loveable. But on just his first day after being born, the steamed bun kicked his father, Xie Yu, in the face with his tender foot.

Summary 2) After Tang Yuan became pregnant with a steamed bun, life was a little difficult, with catching ghosts and also giving prenatal education to their child, yes, prenatal education. But he did teach, he taught for ten whole years. Then Tang Yuan said: Who wants a bratty steamed bun? Who wants me to give them one?

Shou, Tang Yuan, a heavens-defying genius VS Gong, Xie Yu, with off the charts gentleness

Not a scientific/natural pregnancy, no pregnant belly, the steamed bun is born in the final arc (though the steamed bun often appears), fluffy supernatural story, try not to be too scared.

- Description from Novelupdates