Her younger stepsister, Umi, has a gale body with I-cup obese tits. She received sex education at college and is very interested in sex. She comes to me in the bathtub, takes off her apparel in front of me, and seduces me whenever she has the chance. But my rationality can't last long.... Her sexual curiosity gets the better of her," and she crumbs up having relations with a friend of mine.