He turned from being my son to a daddy

As I talked to my young granddaughter about the Thanksgiving Holiday we were discussing who all would be coming. Somehow the subject came up that her Daddy was my son. She became very upset and kept saying he isn't your son he is my Daddy. I tried to explain that he was her Daddy but he was also my son. The more I tried to explain it the more upset she got. She would tell me over and over again eventually almost crying that he was her Daddy. Finally I gave up and just agreed he was only her Daddy. Apparently if she agreed with me she thought he couldn't be her Daddy anymore. Her fear of losing her Daddy far outweighed trying to make her understand that he was a Daddy and a son.