In "The Secret Life of Walter Mitty," how does Walter relate to his wife, and how does she relate to him?

Walter Mitty's wife is an emasculating and meancing presence: She dictates to him what he must do and stifles his masculine sense of adventure. This repression is what causes Mitty to daydream; his dreams create heroism and leadership.

Mitty must drive with his wife to the city for the weekly shopping, etc. When they first arrive in town and Mrs. Mitty gets out to get her hair done, she tells her husband to get overshoes. Mitty retorts, "I don't need overshoes," but she patronizes him as one would a child:  "We've been all through that...."

As compensation for his lack of masculine assertiveness, Mitty's first daydream is that of his being a famous surgeon who "saves the day."  Later, he imagines himself a bombardier, a hero.  Yet, in reality he cannot change the chains on his tires in winter, and despite his attempts at defiance, he acquiesces to his wife's menacing orders and retreats again and again into  daydreams in order to escape his overbearing wife.