>>281650007
Closest thing is probably Yozakura Family.
>MC and FMC have twins after a timeskip.
>Have another child in the epilogue.
>Implied they will have even more because the FMC's family are canonical superhuman baby factories that can shit out kids in six months flat.
The hardest part is having to juggle a larger cast of characters. Also, if the story has physical conflicts in it, you need to explain why the kids can participate in life threatening situations without making your MC look like a dogshit parent. (Assuming you don't take the lazy route and kill them off.)