I, the Weakest Traveler, Start by Taming the gods of the Old World. - Chapter 13: Stone monster

In short: an old lover gave me a little piglet.

Qin Zhuopu, a workaholic, has been single for many years. As he reaches middle age, his family is desperate for a child.

Until one day…

“Mr. Qin, your son is already in primary school!”

“???” I have only had one boyfriend!

Seven years after the breakup, the old lover returned to the wealthy family with a little fat pig in his arms: “Zaizai is a big eater, I can’t feed him. Zaizai’s primary school homework is too difficult, I can’t do it. I’ll give you guardianship from now on! Will you let me go to your construction site to move bricks? Son, say ‘Mommy’!”

Mr. Qin: (No, I couldn’t give birth to such a fat kid!)

Later…

Onlookers: I heard that Mr. Qin has adopted an illegitimate child born to his old lover by some woman?

Mr. Qin: Let me introduce to you, this is my own cub!

- Description from Novelupdates

Jiang Bai woke up one day and found with shock that he had transmigrated to a parallel world that is similar to Earth. There, he was granted a cheat system to help him forge the path of a tyrant in this new world. He was now stuck in this parallel world body, the body of a weak and cowardly person. Join Jiang Bai as he rose to the top in this new world!

- Description from Novelupdates

Shuu is a member of the literary club that can’t write. One day, he gets a mysterious message on his phone from a girl called Eina, and from that impulsive contact, they begin to exchange messages. They talk of things like their shared interest in novels and grow close. However, when they try and meet, they discover a shocking truth. Eina lives… not in the present, but five years in the past! How will their love develop, parted by five years of nights…!?

Four years ago, after a night of drunkenness, she had a relationship with a stranger and fled in panic upon waking up. Four years later, she returns with a soft, cute little bun by her side.“Bad uncle, you're not allowed to bully my mommy!”The man looked at the little bun, who was not even tall enough to reach his waist, and gave a charming smile. “Shouldn't you ask your mommy why you look exactly like me?”