"He's just standing there, watching you eat and looking like he's starving. If he wants to eat with us, let him come to the table."
He should have known it wouldn't work. Should have seen how attached to her son Marge was. He loved her but couldn't tolerate her spoiled son.
Finally, the boy came over, climbed into a chair and asked if he could have his dessert now.
That annoyed Thomas, but at least the boy was at the table, not just watching his mother eat. It was a start.