The marriage is one where Walter is a defeated, emasculated man, used and scorned by his wife. Mitty, clearly unable to be part of the war effort, is too old, incapacitated or mentally unsuitable to fight for his country. His heroism is exerienced only in his dreams, and it is often his wife who punctures them-
The Old Man'll get us through," they said to one another. "The Old Man ain't afraid of hell!" . . .
"Not so fast! You're driving too fast!" said Mrs. Mitty. "What are you driving so fast for?"
"Hmm?" said Walter Mitty. He looked at his wife, in the seat beside him, with shocked astonishment.
He is chastised for driving at a speed she deems appropriate. Then he is questioned and bullied like a child to wear his driving gloves-
"Why don't you wear your gloves? Have you lost your gloves?"
Mitty continues on his mundane errands punctuated with heroic dreams. He is reprimanded again by his wife when she cannot see him in the hotel they agreed to meet at. He challenges her attack for once-
'I was thinking," said Walter Mitty. "Does it ever occur to you that I am sometimes thinking?"
His challenge is however thwarted by her cold threat of medical intervention-
She looked at him. "I'm going to take your temperature when I get you home," she said.
Walter Mitty is so dominated by his wife that the last daydream he has in the story is facing a firing squad, an image he deems better than facing his wife -
...he faced the firing squad; erect and motionless, proud and disdainful, Walter Mitty the Undefeated, inscrutable to the last.