I was visiting my wife's parents. I wanted to give both my mother-in-law and my wife a break from housework, so we came on a hot spring trip with the whole family of four. But I had another purpose. To be honest, I have a strong sex drive, and after three days without sex since returning home, I couldn't sleep at night. I was all geared up to do it tonight in our private room, but my wife fell asleep early, leaving me with a restless night. Then, by chance, I caught a glimpse of my mother-in-law undressing…
