Our parents are out, and my step-sister, in her tiny panties and a tank top, is driving me wild. She's thin, but her ass and tits are perfect. She sits on my lap, grinding on my cock, her panties soaked. I slip my hand under her shirt, cupping her small, firm breasts. She moans, pushing her pussy harder against me. I can feel her heat through my pants. She stands up, turns around, and bends over, pulling her panties to the side. Her pussy is glistening, ready. I free my cock and push it inside her, feeling her tight, wet walls clamp down as I start to fuck her hard.