She says it's what she and President Barack Obama do, and it seems to be working. Their marriage, although tested throughout the years by his political ambitions - for the Illinois Senate, the U.S. Senate and later president - is going on 19 years.
"I think a lot of laughing," the first lady said Tuesday at a White House luncheon with reporters who asked about the Obamas' union. "I think in our house we don't take ourselves too seriously, and laughter is the best form of unity, I think, in a marriage.
"So we still find ways to have fun together, and a lot of it is private and personal. But we keep each other smiling and that's good," she added.
It also helps that Obama is "very romantic."
"He remembers dates, birthdays," Mrs. Obama said last week on "Live! With Regis and Kelly." "He doesn't forget a thing, even when I think he is. . I'll have a little attitude. I give him a little attitude, but he always comes through."
"Got to keep the romance alive, even in the White House," she said.
As for Valentine's Day on Monday, the first lady said her husband would do right by giving her jewelry.
"You can't go wrong," she said.
But Mrs. Obama also said they don't fuss too much over the day that's about celebrating love and affection between couples.
Last year, the Obamas spent Valentine's Day at the Camp David presidential retreat in Maryland.
In 2009, their first year in the White House, they went home to Chicago and enjoyed a quiet dinner at Table 52, a traditional Southern restaurant owned by Art Smith, the former chef of Obama pal Oprah Winfrey.
How will they celebrate this year? Stay tuned.
"We don't make a big deal out of Valentine's Day because my birthday was the 17th (of January)," she told Regis Philbin and Kelly Ripa. She noted, too, that Christmas was just a few weeks before that.
"So by Feb. 14, we're kind of tired," Mrs. Obama said.
For her 47th birthday last month, the Obamas dined at The Source, celebrity chef Wolfgang Puck's restaurant at the Newseum in Washington.