Hidden away in the dark, the siblings find solace in each other's bodies, their hands exploring territory they've been taught to avoid. The brother's hands cup his sister's breasts, his thumbs rubbing circles around her hardened nipples. She gasps, her hips bucking, grinding her pussy against his thigh. He slips a finger inside her, feeling her tightness, her wetness. She unzips his pants, freeing his cock, stroking it until he's rock hard. He lifts her, impaling her on his cock, and they start to move, fucking hard and fast, their bodies slapping together, their moans echoing in the closet.