Sympathize with the newcomer
Try to put yourself in the shoes of the newcomer. I know it’s difficult. But try. That person didn’t do anything wrong. He was just out in the world, looking for love, which is hard to find, and found somebody who happens to be a widow. For all you know, this person has a tough past, too. He may have lost someone. Few people get to be your parents’ age without something difficult happening. So have some sympathy for the person.