Ask the elderly to take care of their children, but the elderly love to play with their mobile phones. After several persuasion, he almost fell out. What if you don't change it?
It is not easy to get rid of old people's habits. Besides, helping children is helping yourself. Old people have no obligation, so if you don't think this will work, don't let the old people take care of the children. You can hire a nanny or send your children to a nursery or something. There is no need for family conflicts. Children should always remember that the old man is taking care of your children.