About going back to the hometown, the young man had a secret affair with his lover's sister

This summer vacation, my girlfriend and I decided to visit her hometown. She had told me about this place, a small rural village with no convenience stores nearby, always giving a sense of boredom. But when we arrived, her parents were out of town, leaving only her older sister, Iroha, at home. She was truly beautiful, with pure white skin and seductive legs. I could hardly take my eyes off her.

In the evening, the three of us slept together, her wearing a thin nightgown that revealed her breasts. She noticed but instead of getting angry, she let me look and touch her breasts, and then she allowed me to have sex with her!!! From then on, I no longer felt bored with this place. I always thought of her. And whenever my girlfriend was away, I and her sister would have sex with each other again and again...