My Grandchild Is Angry Their Father Is Messaging Another Woman

The Yomiuri Shimbun

11:10 JST, October 12, 2025

Dear Troubleshooter:

I’m a homemaker in my 80s. My grandchild, who is in their 20s, talked to me about their father, who is my son. My grandchild looked through my son’s smartphone and found that he has been messaging a woman on the Line app.

My son, who is in his 50s, and the woman seem to have been classmates when they were attending a vocational school and they reunited at an alumni party last year. My grandchild said my son and the woman apparently have been trying to arrange a date and time to meet again.

My grandchild’s mother has been busy taking care of her own mother, who is hospitalized. In light of the situation, my grandchild is angry and said: “He’s so inconsiderate at this difficult time. I felt like punching him, but I held back.” My grandchild also tells me they have no appetite.

My grandchild fears that their parents might divorce if my daughter-in-law finds out about the relationship between my son and the woman, so my grandchild asked me to talk to my son.

First, I apologized to my grandchild and said, “I’m sorry that I didn’t raise him well.” But I also told my grandchild, “It isn’t good to snoop through other people’s things. You know it’ll negatively affect the situation when I talk to your father.”

I’m going to talk to my son and tell him that his womanizing behavior has upset his child. How should I approach my grandchild from now on?

B, Kanagawa Prefecture

Dear Ms. B:

I am glad that your grandchild has you to talk about their father’s issues. They are becoming a kind person, who loves their mother, and has a strong sense of justice.

It is okay to scold them for secretly looking through their father’s smartphone, but it is more important to praise your grandchild’s good aspects.

Relationships between a man and a woman are often complicated. Your son may not even know what he wants with this woman. When you talk to your son, it is better not to mention that your grandchild saw his messages on his smartphone.

It might be best to start by simply telling him that his child is hurt and they suspect that their father may be secretly seeing another woman. Hopefully, such an approach will serve as deterrent and nothing will happen, but nothing can be predicted.

Tell your grandchild that you will be with them no matter what happens and that you are ready to listen to them about anything. Give them the support they need.

Masahiro Yamada, university professor