] This has really been bothering me. Why is John such a toady, even towards his own wife?

This, from the end of Ch. 41:

(Fanny) even proceeded so far as to be concerned to find that Elinor and her sister were so soon to leave town, as she had hoped to see more of them; an exertion in which her husband, who attended her into the room, and hung enamoured over her accents, seemed to distinguish everything that was most affectionate and graceful.