I was sure that my super shy stepsister would never tell her parents, so I secretly played with her nipples every day, but recently she has become super sensitive and has a premature ejaculation problem, and just a light touch on her nipples makes her drool and cum! This is bad! I thought I'd gone too far, but then my stepsister suddenly turned into an S-class perverted girl, and now she wants my dick for even more pleasure! I planted the seed myself, but I never expected her to become this erotic!