1/3
3 Years of Service
Friend, why double standards?yeah, so far what you are asking for doesnt really exist outside hentai, and even in those its cause you can skip a decade or two in a flip of a page and it makes sense, or in the case of one where they are like cherub elves or something they get to breeding age super quick. anyway, current existing story line closes to what you are looking for has been mentioned couple times, 23 sisters.
I have hopes that My New Family sequel will one day show the lead harem LI's conviction that all the babies will be daughters and they will all one day marry the MC just like them. Considering the core of his harem is 3 redhead sisters, blonde cousin, grandma, mom, aunt, and their boss who is basically family, its a whole lot of potential. Mild dom with some harem women, the aunt and boss kinda have to be owned to shut them up.
If the case of Maou-sama seems to you too fantastic, then the situation with the "My new family" is as fantastic, if you think.
If we take into account that the MC sperm is magical and allows a woman to become technically younger, as it become with grandma, it turns out that the MC in itself has all the makings to be a demigod that does not know aging. And in this case, he can survive until the moment when all his daughters will become marriage age, and then the second wave of marriage will take place
BTW I think that a red-haired german doctor with tatto should be included in the family by the principle of "must have!".