Through the slightly ajar door, the brother catches a glimpse of his sister's forbidden fruit, her round ass illuminated by the soft moonlight streaming in through the window. Unable to resist, he approaches her silently, his heart pounding in his chest. She senses his presence and turns to face him, her eyes filled with desire and anticipation. Without a word, she bends over, presenting herself to him. He unbuckles his pants, releasing his hard cock, and positions himself at her entrance. With one swift thrust, he enters her, causing her to gasp in pleasure. He begins to move, slowly at first, allowing her to adjust to his size before increasing his pace, filling her completely with each powerful stroke.