Miyuki teased her unpopular younger brother as a joke. Misunderstanding it as a real invitation, the virgin brother inserted his cock into his sister immediately after their parents left. Miyuki reached climax from the sheer intensity, but the brother, inexperienced with women, didn't notice and continued to thrust recklessly. Even after climaxing, the continuous piston motion chased her with pleasure, causing her to orgasm repeatedly, and she was kept coming until their parents returned. Completely ignoring his sister screaming, "I'm... already coming!!", he kept her climaxing with his high-speed piston fucking!