Netflix’s new series, The Crown, is a fascinating portrait of the unusual marriage between Queen Elizabeth and Prince Philip and highlights a cutting-edge marital dynamic: one in which the wife, not the husband, is head of the household.

When Elizabeth II was named Queen in 1952, Prince Philip forfeited his naval career to support his wife—which was, as Julie Miller writes in Vanity Fair, “an uncomfortably advanced spousal dynamic, especially for a headstrong officer in the 1950s.”

Adds Miller, “If having to walk several paces behind his bride was not emasculating enough—a requirement that causes Philip to bristle in the series—the queen also rejected his request to give their children his surname on advice from Churchill. ‘I am the only man in the country not allowed to give his name to his children,’ Philip said, according to a biography of Elizabeth by Sally Bedell Smith. ‘I’m nothing but a bloody amoeba.’”

Today, this sexual dynamic is gaining ground. According to the U.S. Census Bureau, as of 2009 the percentage of wives who out-earn their husbands is 28.9, compared to 17.8 in 1987. Overall, women are outpacing men on college campuses and are gaining ground in the workplace like never before. They’re becoming richer, of their own accord, by the day.

This rise in women’s status is almost always hailed as a boon for society, and it may be. But it is rarely a boon for love.

It’s one thing for men and women to be flexible about gender roles and another to reverse them entirely. Human nature doesn’t change because society does. Just as women are emotionally invested in the home in a unique and primal way, men have a visceral need to provide and protect. That is how most men and women gain a sense of self-worth. When a wife usurps her husband’s role, the game simply changes.

That is not to say no married couple can successfully navigate a role reversal. It is only to say that it’s rare. Even today, approximately 30% of married women with children choose not to be employed; and in families where both parents are employed, “70% consist of fathers who earn more than mothers.”

The overarching problem when women make more is they tend to use this money as a means of control. “When a man makes a lot of money and a woman doesn’t, there may be fighting over money—the actual dollars and cents of living and how she spends it. When a woman makes a lot of money and the man doesn’t, the fight isn’t exactly over money but over power: She expects to have more of it,” writes couples therapist Jane Greer, Ph.D.

When a wife pulls rank in this way, the marriage is dramatically altered—particularly in the bedroom. “According to psychologists who see couples struggling with [a shift in economic power], many relationships follow the same pattern. First, the wife starts to lose respect for her husband, then he begins to feel emasculated, and then sex dwindles to a full stop,” notes Ralph Gardner, Jr. in New York magazine.

Ironically, it isn’t just men who are uncomfortable being second in command. Women don’t like it either! Despite the gains women have made economically, most do not want to be more powerful than their man. That is the nature of sex and sex roles.

It is also the reason successful marriages tend to be traditional in nature. A traditional marriage does not mean the wife never works outside the home or the husband never changes a diaper. Few marriages today look anything like that. All it means today is that the husband makes more than his wife.

“American wives, even wives who hold more feminist views about working women and the division of household tasks, are typically happier when their husband earns 68% or more of the household income,” writes W. Bradford Wilcox, director of the National Marriage Project at the University of Virginia.

This approach to love swims with the tide, rather than against it. Unfortunately, we are up against a culture in which women are positioning themselves to become the more successful sex. How will we marry this brave new world with the reality of human desire?

Suzanne Venker is an author and cultural critic who writes about relationships, marriage and work-family issues. Her fifth book, The Alpha Female’s Guide to Men & Marriage: HOW LOVE WORKS, will be published in February 2017. Her website is www.suzannevenker.com.