1.
The Dregs is an old-school ABO novel.
It's a crematorium story where an Alpha scumbag mistreats his Omega, then comes to his senses only after the Omega's heart has turned to ash, and the Omega dies unexpectedly in the end.
When Guan Ning wakes up, he finds himself in an epilogue set twenty years after the story's timeline, as the shou protagonist who shares his name.
He has no old flame, and his Omega glands are dormant, but he does have the youngest three-time Best Actor Alpha in history as his son.
Guan. Little Guy. Yuan: Dad, I'm almost twenty!
Guan. No Idea Who the Father Is. Ning: Sure, young man. So who's your biological father?
Guan Yuan: ...I think a few of my uncles are pretty great.
Uncle A: Pick me!
Uncle B: I'm up for it!
Uncle O: If he can do it, so can I!
Zhou Zhuchuan, the cast-off husband: What? My son is rebelling and breaking my heart.
2.
Is the youngest Best Actor in history, Guan Yuan, dating someone?
Gossip account: The rumored mysterious lover.
Haters: Oho!
Bystanders: They look like a married couple. They suit each other.
Fans: It's either big brother or little brother.
A week later, the variety show Big Friends at Home is announced.
Guan Yuan posts a picture: My dad!
3.
Zhou Zhuchuan, twenty years ago: Where's my wife? Where did my gorgeous wife go?
Zhou Zhuchuan, in the intervening twenty years: Being cremated. Do not disturb.
Zhou Zhuchuan, twenty years later: I'm reborn. Thanks.
Note: One-on-one from beginning to end, not a multiple-choice romance, and the gong is not a scumbag. The shou is the original person, both are sexually inexperienced, no real-life inspirations, completely fictional setting, and the ABO world includes original worldbuilding.
Theme: Building a happy family