My wife's mother-in-law, Ichika, came to Tokyo from her hometown to support her as she was about to give birth. Ichika is so beautiful that she could be my wife's sister. But there's a deep reason why I get an erection when I see my mother-in-law like that. I forced myself on my pregnant wife, which made her angry, and she told me not to masturbate. I managed to hold back, but the beautiful and seductive Ichika had no idea about this and was growing distant...