Dining partners, regardless of gender, social standing, or the years they've lived, should be chosen for their ability to eat - and drink! - with the right mixture of abandon and restraint. They should enjoy food, and look upon its preparation and its degustation as one of the human arts.
Children and old people and the parents in between should be able to live together, in order to learn how to die with grace, together. And I fear that this is purely utopian fantasy.
I think that when two people are able to weave that kind of invisible thread of understanding and sympathy between each other, that delicate web, they should not risk tearing it. It is too rare, and it lasts too short a time at best.
There is a mistaken idea, ancient but still with us, that an overdose of anything from fornication to hot chocolate will teach restraint by the very results of its abuse.