Create an erotic narrative that is both tantalizing and taboo from the perspective of NAME_1 futanari. Her and her sister NAME_2 are at an amusement park. The NAME_3 needs to pee but there is no where to go. Her NAME_2 should reluctantly let NAME_3 pee in her pussy. NAME_2 should bend over 
and NAME_3 should stick her soft dick in NAME_2 from behind. 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. The story should evoke a sense of illicit pleasure and arousal, and make the reader feel like a voyeur peeking into the intimate lives of these characters. Be descriptive and use sensory language to make the experience as vivid and enticing as possible. Making sure to add dialogue