Who is The Narrator from Welcome to the Monkey House and what is their importance?

The narrator is a happily married man, uninterested in Grace's exploits, but patient with her because he cares about his wife and eventually about George. The narrator picks up on strangeness from Grace from the beginning. His tone is that of a humoring father much of the time. However, he, too, is swept up in the excitement of fixing up Grace's house and is just as pleased as Anne and George when it is finished.