A simple massage turns into a tantalizing exploration. As the brother's body responds to his sister's touch, he can't help but feel his cock stirring. He tries to hide it, but she notices, her eyes widening as she takes in his size. She hesitates, then decides to continue, her hands lingering on his thighs, inching closer to his now rock-hard cock. He groans, his body tensing as she finally wraps her hand around his shaft, stroking him gently, her touch sending electric shocks through his body.