Mitsuki teased her unpopular younger brother as a joke. Her virgin brother, misunderstanding that she was seriously inviting him, inserted his penis into his sister immediately after their parents left. Mitsuki reached orgasm from the sheer force, but her brother, inexperienced with women, didn't notice and continued to thrust his hips recklessly. Even as she orgasmed, the relentless pistoning chased her through waves of pleasure, making her orgasm repeatedly until their parents returned home. 'I... I'm already coming!' her sister screamed, but he completely ignored her, making her orgasm over and over with his explosive piston thrusts!
