(RealSimple.com) -- A lengthy separation -- and a surprise trip to Paris -- caused this husband and wife to realize that their marriage could be saved. 

Mary L. Tabor and Del Persinger Washington, D.C. Married 26 years 

Mary was still in her nightgown and robe, sipping a cappuccino in the kitchen of the Washington, D.C., brownstone she shared with her husband, Del, when he walked in and announced he wanted to live alone. They had been married for 21 years. 

"I didn't know what had hit me," Mary, 64, recalls of that fall morning in 2005. "I wondered, does he have a girlfriend? A boyfriend? I had no idea what was wrong." 

Although the couple's relationship had been strained for a few months, Mary simply assumed they were going through a rough patch. She attributed Del's loss of interest in sex and his suddenly quick temper to stress from his high-pressure job as a financial analyst. 

"Del was so on edge that he would yell at me about every little thing -- like a knife accidentally placed in the dishwasher with the point up," says Mary, a writer and a teacher. Still, she figured that things would soon return to normal. 

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For Del, the decision had been a long time coming. Increasingly restless within his marriage, he wondered whether it was holding him back from leading a more exciting life. "I knew the problem wasn't Mary -- it was me," he says. "And I felt I needed to work through my mixed emotions alone." 
What did Mary assume?
 Mary simply assumed they were going through a rough patch.