#this phenomenon exists irl and it's called heteropaternal superfecundation!

[doodleferp]

I hope Knives and his goons don't find out about Vash and Aris kids

They find out once the family leaves Kasted and makes for Home. But the thing to remember is that Knives doesn't hate Vash and Ari -- the Gung-Ho-Guns do. Knives just believes they're misguided and need to be shown why humanity is so terrible. He doesn't hate them, and he wouldn't hate their children. Knives has no ill will against the quadruplets because they have done nothing other than be born into a world stacked against "their kind" from the start. They don't know how dangerous humans are because they haven't seen it, so it's not their fault they're misguided. In Knives's mind, the quadruplets are the only truly innocent party in this conflict and he won't put their lives at risk if he can help it. He may even use them as another excuse to eliminate humanity.

But fun fact! The quadruplets are not the first kids that Ari's had! Ari and the twins have had a long, tumultuous history, and they were actually a throuple for several decades. At one point in their past, the boys knocked her up and she had twins! Two beautiful little girls named Indira and Sylvia, fathered by Knives and Vash respectively. Like their younger siblings, Indira and Sylvia grew at twice the rate a normal human would. Unfortunately, something...rather unfortunate happened to the girls when they were about six or seven, and they are now presumed dead or worse. The trauma from it drove them apart and led Ari to swear off having children for a very long time.

Idk how to work them into the 1998 timeline since Ari and the boys would only be together for a short time, but I have figured out a way to put them in Stampede. I'll put up the full backstory if anyone wants to hear it!