My sister was doing her homework in the kotatsu when I noticed that she had fallen asleep, and her legs in the way! When I looked inside, I saw her legs wide open and her panties were completely exposed. Even though I knew it was my sister, I couldn't resist the temptation of her panties, so I sneaked in and watched her up close! As I was watching, I was tempted and started touching my crotch, and my panties started to get wet! However, my parents came back and interrupted the act... but my sister, who was actually awake, grabbed my wrist and pressed it against my crotch... My horny sister asked for incest even though our parents were nearby!