What is the theme of "Mr. and Mrs. Dove" by Katherine Mansfield?

Insecurity is an important theme in the story. Reggie is very apprehensive at the prospect of asking Anne's parents for her hand in marriage. Reggie is full of self-questioning and reproach; he lacks the necessary confidence for a successful suitor. Anne herself doesn't help matters much by continually laughing at him, undermining his already fragile self-esteem.
Reggie's chronic insecurity leads to another of the story's main themes: control. Anne seizes on Reggie's lack of confidence in himself to lead him a merry dance. Her behavior towards him indicates that she's cruelly toying with his affections. This clearly isn't a relationship between equals. For a woman of her time and class, Anne enjoys an extraordinary degree of control. The doggedly loyal way that Mr. Dove follows Mrs. Dove around symbolizes Reggie's subordination to Anne.
Although a dejected Reggie briefly plucks up the courage to walk away from Anne, he soon turns back, answering to her beck and call. He cannot move on from Anne, literally or figuratively, and so cannot move on with his life. Traditional gender roles have been reversed; it is the man who is dependent on the woman, rather than the other way round.