Power cut on a winter afternoon caused Rishi and her step sister Radhika to tuck together to feel warm. But they didnt know that coming so close for a man and woman no matter what the relation is could lead to something different. And that is what happened , within few moments they started to enjoy each others touches and then caressed each others private parts to feel more warm. Rishi was hard and Radhika , his sister , was wet down there. What happened next is shameful as per societal norms but very natural as per human instincts.