Tsumugi and I have been married for a few years; she is a wife who is always devoted to her family. Today she also prepared lunch for me, and it feels as happy as being newlyweds. Yamashita is my junior; I often see him staring at his phone, even while eating. It turns out he is using a dating app, and his targets are married women. "Married women often feel unsatisfied with their sexual desires," "they are the easiest to flirt with and the easiest to 'play' with." I think that is only a minority; I don't believe all women are like that, especially my wife. Yamashita said he wanted to try with my wife, and I accidentally agreed. So I invited Yamashita over for dinner and then made an excuse to go out, leaving Yamashita alone with Tsumugi for three hours. When I returned, everything seemed normal, believing nothing had happened. But since then, my wife seems to be changing more and more...