NACR-258 Son's wife Miku Ikuta

My son’s daughter-in-law, Miku, who lives with me, suddenly got angry and talked about her son’s affair. My son doesn’t answer the phone call, so when I ask him, he seems to try to deceive him. Miku-san was calmed down, but his anger didn’t seem to subside, and he said, “I’ll have an affair too!” What was the action taken by my father-in-law who felt pity for such a daughter-in-law?