The siblings, hidden from the world in their secluded home, can no longer deny their carnal longings. She sits on the couch, her legs spread wide, fingers teasing her wet slit. He watches from the doorway, his cock tenting his pants. "You know I've been watching you," he growls, advancing on her. She moans, arching her back, her nipples hard. He pushes her legs wider, his mouth descending to her pussy, licking and sucking. She cries out, her hands fisting his hair, grinding against his face. He stands, unbuttoning his pants, his massive cock springing free. She licks her lips, eager to taste him, but he pushes her back, positioning himself at her entrance. "I'm going to fuck you now," he says, his voice hoarse with desire. She nods, her eyes wide, ready to give herself fully to her brother.