Write a taboo erotica about 2 twin futanari sisters NAME_1 and NAME_2 having quickie with their little sister NAME_3. The 3 of them realize they have 5 minutes before their parents get home. The 3 are wearing schoolgirl outfits. The 3 of them need to be quick and only pull their panties to the side leaving their outfits on. NAME_1 lies down on her back NAME_3 straddles and lowers herself onto NAME_1's dick. NAME_2 pushes NAME_3 forward and joins NAME_4 in NAME_3's  pussy. As NAME_1 and NAME_2 cum they knot NAME_3's pussy unable to pull out. Add and expand and details. Make it extremely sexual and add dialogue.