Mr. Robert is the live-in companion of Grandma Sands, Mrs. Watson's mother. Right from the get-go, it's clear that Willona doesn't approve of her mother's living arrangements. For one thing, she sees it as an affront to her late father, who passed away some twenty years before.
There's no hiding the distaste that Willona harbors toward her elderly mother's new beau. She's not comfortable with the relationship she has with Mr. Robert, not least because neither she nor her late father ever knew him or anything about him. To Mrs. Watson, this Mr. Robert guy is a total mystery.
But as Grandma Sands explains to her, things are different now from what they were when Willona left home. Life has moved on, and so has she. Everything changes, especially over twenty years, which is how long Willona's father has been dead.
In any case, Grandma Sands and Mr. Robert fulfill each others' needs as they enter into their twilight years. Both are old people in desperate need of company in order to fend off the loneliness that is so often a problem for the elderly. Whatever Willona might think, Mr. Robert is just right for her mother, her "dearest friend" in the words of Grandma Sands.