Considering that few couples make exactly the same salary, odds are at some point in your relationship you'll need to navigate the difference between your incomes — and all the feelings that come with it.

A Pew Research Center study found a striking statistic: 40% of American families’ primary breadwinners are mothers, and 37% of those, an estimated 5.1 million, are wives who make more than their husbands.

But the same Pew study found that having a female breadwinner was reportedly stirring up trouble in marriages. Why? Well, 50% of respondents felt it was harder on a marriage, and 74% said it was harder to raise children.

Jonathan Alpert, a Manhattan psychotherapist and author of "Be Fearless: Change Your Life in 28 Days," sees many patients in this situation.

"Open communication is the key," says Alpert. He suggests couples list out their expenses and respective earnings to help devise a plan for saving and paying bills. “If salaries are comparable, then splitting it down the middle works. In the case of a disparity of salaries, I suggest that each person pay a percentage of their respective salaries. This way people will feel they are contributing in a fair way."

Here, three successful men share how an income differential plays out in their relationships.

"She Wore the Pants": The Self-Esteem Factor

Alan, 40, is a successful accountant at a small firm he helped start in Bethesda, Maryland. Yet his wife, a doctor, still earns more than him. At first, Alan was embarrassed. “It was a male ego thing,” he says. “There was just something about it that made me feel inadequate. I knew it was illogical.”

Three years ago, after nearly six years of marriage, his resentment bubbled over when his uncle asked why they never had children. “I made a rude comment about how my wife was too busy wearing the pants in our relationship to be a mom,” says Alan. “And then instantly regretted it.”

That evening, Alan and his wife discussed their salary differences and the toll it was taking on his self-esteem for the first time since she graduated from medical school. “She helped me gain perspective. There are so many more important things to worry about in life than who makes more money,” he says.

“Now I’m able to see that being grateful to have a job, a roof over my head, and a talented and successful wife who loves me no matter how much I make, is more than enough," he says.

"I Always Thought I Would Make More Money"

A year and a half ago, when Adam, 28, decided to go back to school for his MBA, he was earning more than his wife.

As an account executive for an advertising firm in New York City, his wife makes good money, but Adam’s salary as a financial analyst combined with his bonus was still higher.

The pair was able to save up enough to cover Adam’s tuition while his wife supported the two of them. “I always thought that I would make more money than my wife,” says Adam. “I know it might sound archaic, but I believe that men are naturally supposed to be providers and that’s what I want to be able to do for my family.”

He isn’t bothered by his wife’s breadwinner status — for now.

“Honestly, I’m OK with her making more money than me right now, because I see this situation as temporary,” says Adam. “She may be the only one working right now, but I know that the bulk of the savings we’re living off of come from my old salary. And I expect to return to making even more once I graduate.”

A Change of Heart

“My wife often makes more in a day than I make in a month,” says Michael 45, a freelance photographer and father of two, whose wife is a vice president at a financial firm.

These days his income can be sporadic, but it wasn't always that way. Years ago, Michael was a photo director at a magazine, earning six figures and flying cross-country weekly for photo shoots.

“I was also a jerk,” he admits. Even though his wife was also working full time,“I expected her to do everything — cook the dinner, do the laundry, raise our two kids — since I was never home," he says. Then, Michael was laid off.

“I didn’t know what to do with myself at first,” he says. “Then I realized that my daughter played soccer really well, and my son was terrible at the oboe. These were all things that a normal dad should have known, but I was so busy with my job that I didn’t.”

Michael saw his job loss as an opportunity to take back some responsibilities around the house, easing his wife’s stress and growing closer to his kids. “I realized I was missing out on a lot by only focusing on my career,” he says.

Now, he freelances as his wife climbs the corporate ladder.

“I like that my wife is being rewarded financially for being intelligent,” he says. “If that makes me unmanly, so what? I still get to pursue my passion, only now I get to do it on my own time. And as long as she never acts the way I did when I was the breadwinner, I don’t think I’ll ever mind.”