Create an erotic narrative that is both tantalizing and taboo from the of NAME_1. Her and her mother NAME_2 are at a shopping mall. The NAME_3 needs to pee but there is no where to go. NAME_1 should reluctantly let NAME_3 pee inside her pussy. NAME_1 should lift her skirt pulling her panties to the side and NAME_3 should stick her soft dick in NAME_1 from behind grabbing lunas hips as she starts pissing. The futanari cock should then start getting erect being in her sisters pussy. Without speaking they slowly being unsure if the other really wants to have sex. NAME_1 would grab her sister's ass pulling her deeper and NAME_3 deposits her seed in to her sister. The story should evoke a sense of illicit pleasure and arousal, and make the reader feel like a voyeur peeking into the intimate of these characters. Be descriptive and use sensory language to make the experience as vivid and enticing as possible. Making sure to add dialogue.  Write as if you were NAME_1.