The May-December bliss is brief — especially when money gets tight.

Both men and women are more satisfied with younger spouses, new research says. But couples with larger age gaps saw greater declines in marital happiness over six to 10 years than closer-in-age couples — and were less resilient to economic shocks like job loss or bankruptcy.

The study, published in the Journal of Population Economics, used 13 years of data from the Household, Income, and Labor Dynamics in Australia (HILDA) survey to track how a “major worsening of finances” in the past year affected couples’ self-reported satisfaction with their marriages.

“When couples experience this worsening of finances, the couples with larger age differences report larger declines in their marital satisfaction than couples that are similar in age,” study co-author Terra McKinnish, a professor of economics at the University of Colorado, told Moneyish. “That suggests that the couples with larger age differences are having trouble adjusting to the change in their household finances.”

While the data didn’t delve into driving forces, McKinnish speculated husbands and wives with larger age gaps might struggle to agree on spending priorities — travel and leisure, saving for retirement and having and raising kids, for example — and decide how to cut back. (The dataset included only heterosexual couples, but it’s “perfectly reasonable” to think a similar dynamic might bear out in same-sex couples, the prof said.)

“You’re looking at a generation gap, which usually impacts values, beliefs and upbringing when it comes to finances and money,” Los Angeles-based licensed psychotherapist Stacy Kaiser told Moneyish. Another factor might be a “power struggle,” she said, with the older partner trying to take charge.

Kaiser suggests a two-pronged approach after a major financial blow like a stock market crash or costly health incident: having an open, honest sit-down aided by a psychological or financial counselor, and compromising on a plan that suits both parties — or at least minimizes the discomfort.

“It could be individual things that you are cutting back on … or a shared thing,” she said. “Like you both love to go to sporting events or concerts, and so you cut back and you’re both impacted.”

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Write out a specific plan for budgeting, spending and saving, Kaiser advised, and lay out exactly how you will execute it: “Are you going to pick up separate jobs? Is everybody going to try and save $500 a month on their own?” she said. “Are you cutting back in small ways or large ways?”

Couples should also give themselves room to deal with the emotional toll of belt-tightening — complaining, crying and pounding a pillow are all fair game — and decide how far the news should travel. Fights often erupt after one partner blabs to family or friends and the other gets upset, Kaiser said.

Fantasy may also play a role in the fallout, said psychotherapist Elisabeth LaMotte of the D.C. Counseling and Psychotherapy Center, with the younger partner envisioning “unlimited financial resources” and the older one imagining fresh, exciting sex. “Inevitably life throws adversity at every couple, whether they have an age difference or not,” she told Moneyish. “So if there is a lot of fantasy built into a marital dynamic, the adversity causes the fantasy to come crashing down.”

Try seeing the crisis as a way to learn “emotional maturity and resilience,” LaMotte suggested. “Whether you need to get professional help, whether you need to go into deep reflection, explore and face the reasons that that was not a realistic expectation to begin with,” she said.

New York-based relationship specialist Rachel Sussman — who says she’ll typically see non-working younger women with older, wealthier men — urged pursuing those awkward talks about savings, retirement money and life insurance before even tying the knot. (“I can’t tell you how many women I see who stop working and say, ‘My husband’s going to take care of me’ or say, ‘I never even bother looking at the tax returns,” she told Moneyish. “That’s ridiculous.”)

Above all, Sussman said, honesty is key. “If your business is running into trouble and you think you’re going to take a hit, you want to accept that and talk about it with your partner as soon as possible,” she said. “You have to try really hard to put emotions behind you and have a solutions-focused discussion.”

“There’s no time for shaming or blaming or hysterics,” Sussman added. “Get to work.”