Characters who are human beings and have flaws are one of my biggest kinks and you hit that one hard with this story. Your Millicent is grand. She is aware of her flaws, excuses some of them to herself, and stands up for herself. As for Charlie, this is one of the better portrayals that I've seen of him. He is who he is, doesn't suffer fools gladly, is oblivious to the people around him at least as often as not, and still has a heart as big as it gets.
I was glad to see them actually talk it out at the end, instead of stomping around, throwing out nasty-grams, and not communicating (one of my anti-kinks when done too often or as a convenient plot device). This is a story I'll come back to and read again.