A curious sister, her eyes gleaming with innocent curiosity, watches her brother as he towels off after a shower. His thick cock, semi-hard, catches her eye, and she can't help but stare. He notices her gaze, and instead of being embarrassed, he stands tall, letting her take in his form. She licks her lips, her heart pounding, as she tentatively reaches out to touch him, her fingers wrapping around his shaft. He groans, growing harder in her hand, as she explores his body, her own desires awakening.