Bored and restless, I stumbled upon my gorgeous, brunette stepsister, Michelle, sneaking cash from our parents' stash. Enraged, I confronted her, our argument escalating until she challenged me to punish her. With a devious grin, I agreed, pushing her against the wall, my hand sliding up her thigh, feeling her tremble. Her breath hitched as I whispered, "You're gonna pay, sis." My fingers found her wet panties, sliding inside her warmth. She gasped, her body betraying her as I fingered her, my other hand pinching her hard nipple. Her moans filled the room as she confessed her theft, begging for forgiveness. But I wasn't done yet. I unzipped my pants, my hard cock springing free. I turned her around, pushing her against the wall, and plunged into her tight pussy, fucking her hard until she came undone, her cries of pleasure echoing through the house.