As I walked past my sister's room, I couldn't help but notice her big, round booty sticking out from under her tiny shorts. I couldn't resist the urge to tease her a little bit. I crept up behind her and gave her a playful squeeze, causing her to jump in surprise. We both burst into laughter before things took a more seductive turn. Before I knew it, we were both stripped down to nothing, our nude bodies pressed together as we explored each other in a frenzy of passion. Her big booty bounced as we moved in perfect harmony, the sensation of our bodies intertwining driving us both wild. It was a forbidden thrill, the taboo nature of our actions only adding to the intense pleasure. In that moment, nothing mattered except the sensation of two nude girls fucking in perfect harmony.