"Aaah ... Father-in-law! It feels good ... It feels so good!" An incredible sight was spreading in front of me. When I got home earlier than usual, I witnessed my wife having sex with a man ... and the partner was my father. My vision went pitch black and when I noticed it, I was lying on the sofa in the living room. "Oh, thank God. It looks like you woke up. I was worried." "... Oh. Mother-in-law ..." It was mother-in-law, Natsukawa Midori, who is my father's remarried partner from two years ago, called out to me. "Oh, mother-in-law ... The truth is ――" ―― I gave up and confessed everything. Midori kept her calm and listened to me from beginning to end. When I finished talking, she nodded a little, convincingly. "Honestly ... I thought that was the case after all. Daijiro-san's appearance has been strange recently ... Thank you for speaking honestly. I'm more worried about you. It would have been quite a shock to witness the moment of affair ... ?" "Yes ... That is ... Already ..." "... I understand. Just leave this to me ..." Midori said that, she gently leaned her body next to me and "Hey ... I think we should act together. With stronger connection than ever ... Yes, as partners who vow to revenge."