It had been a long time since I last visited my wife's parents' house. So, I was a little taken aback when I saw Chihiro-chan (my wife's sister) with a different look. I had always thought of Chihiro-chan as a child, but now she had become a grown woman. I started to think of her as a woman. When my wife went out and we were alone, I couldn't suppress the sudden surge of lust and ended up violating Chihiro-chan.