My mother-in-law came to Tokyo and decided to stay at my husband's house. However, the house was small, and my husband and I had to sleep in a river-like position with her. My mother-in-law was a slender woman with large breasts, and I couldn't sleep because I was too sensitive. The next day, the three of us were still sleeping in this river-like position. In the middle of the night, I could hear the panting coming from my mother-in-law. I looked at her and tried to comfort myself. The next day, after confirming that my wife had left, I hugged my mother-in-law and told her what I had seen the day before. When I pressed my already stiff lower body against her, she knelt down, which felt good. And at night, the three of us were still in this river-like position. When I woke up with a strange feeling in my lower body, my mother-in-law was sucking my crotch…