Who is Mr. Beaver from A Handful of Dust and what is their importance?

Mr. Beaver is a young man who will leech on anyone who will provide him a path to the upper class social society. His father was wealthy, but died and left him and his mother struggling. Before Beaver meets Brenda Last, he is only known for filling in for absent husbands on the social scene. No one really knows him and what they know they don't like. Brenda Last falls for Beaver, but from the start he doesn't care much for her. He spends the summer with her taking advantage of the fact that her closest friends are high society women and men. In the end, when Brenda has taken him as far as she can, he leaves her and takes some time away in New York.