The brother, a beast unleashed, sees his sister's confession as a green light to his pent-up lust. He pounces, his hands roaming, exploring every inch of her soft, yielding body. She gasps, her eyes wide with surprise and fear, but her body betrays her, arching into his touch, her nipples hardening against his palms. He grinds against her, his cock a steel rod against her thigh, whispering filthy promises in her ear as he marks her as his own. She's his now, his to claim, his to defile, and he's more than ready to burst forth into their new, taboo existence.