Jeff feels his body changing as an heat and a need to breed or be breeded starts to fill him/her as her clothes ripped off from the nine tails that grew out of her tailbone and a pair of c-cup breasts grew out as her cock grows and hardens to 15 inches and egg sized balls filled with cum waiting to breed a female hanging below it, as a pussy opens behind it. Before she loses herself to the heat she has her parents pay no more mind to the changes and start fucking more and make it so no one enters or leaves the house for now before she couldn't hold herself back anymore as a scent enters her nose. She exits out of her room following it to her sister's room to see her on the floor in her new form of a female anthro fox girl/vixen with breasts that had grown out from c-cup to dd-cup as she pants in heat fingering herself before she sees and opens her legs to her. "Please take me!" Sarah begs her sister seeing her hardened cock standing at ready.
New knowledge enters Jeff's/Ami's mind as she steps over to her needy sister, of kitsunes have a great amount of power and thus had been worshiped in the past and still area today with some having become goddesses due to the worship they got thought none rule aside from a couple of kingdoms/empires in Asia that still exist to this day, and how they only birth girls and mostly they are born as kitsunes or less often anthro foxes, rarely would they birth a child of the father race and more rarely a male leaving them as an near total female/futa race as futas in a 50/50 chance for each girl they birth thus allowing them to not be fully reliant on other races to breed and have kits insect is allowed as well to a point, said futas also take more than one mate as well. The mates of a kitsune will share the kitsune's lifespan which is centuries if not millennia depending on the kitsune unless they are a goddess, then they and their mates are ageless thought other means can kill them, those who the kitsune has sex with but aren't mates won't share it though. Ami lines up her cock with Sarah's wet virgin cunt and thrusts into her as the two moan in pleasure. "Yes! Breed me sister! I've wanted it for years!" Sarah moans as Ami fucks her going deeper with each thrust. "Then take it all you needy sister slut! I'll fill you with my seed so you will carry my kits in you!" Ami replied as she went faster to breed her sister as she grabbed Sarah's breasts and played with them
Ami soon hits a barrer as she still has three inches left out of her sister telling her she is hitting her sister's cervix, the thought of cumming directly into her sister's womb to breed her makes her thrust harder into her to break into her womb as she shapes her sister's pussy to only have her cock fit in her to feel pleasure from only Ami, the thought of seems to make Sarah more horny. "Ah yes! Break it in! I'm your cum slut and breeder alone!" Sarah moans as she climaxes but Ami held herself back as she eventually forced her way into Sarah's womb before cumming into it as the futa hits the back of it, making her climax hard as her eyes roll up and her belly bloats up making her look as she is six month pregnant when Ami finished. Ami pulled out of her as the heat went away before she...