How do married couples stay happy? Scientists say they know.

Sure, you'd love to grab your guy and catch a cheesy flick, take a stroll, or linger over wine and dessert. But before you think, "Yeah right, who has the time?" get this: According to new research from the University of Denver, spending time with your guy without discussing finances, kids, or daily hassles is not an indulgence--it's top priority, and crucial for your union.

"The more you invest in fun and friendship and being there for your partner, the happier the relationship will get over time," says Howard Markman, a psychologist who co-directs the university's Center for Marital and Family Studies.

"The correlation between fun and marital happiness is high, and significant."

And for men, having quality time with you is even more important, since men are more likely than women to call their spouse their best friend. Awwww....

The long-term study looked at 306 Denver-area couples, and asked them to agree or disagree with statements from a "friendship scale" such as, "We regularly have great conversations where we just talk as good friends," and "My partner really listens to me when I have something important to say."

The research supports previous findings published in the Journal of Personality and Social Psychology, which showed sharing in new and exciting activities is consistently associated with better marriages. However if your idea of "something new" means watching Lost together, Markman says no dice, since activities like watching television or using the Internet don't build those lovey-dovey connections.

But one roadblock to achieving this quality time together is that many couples have different ideas of what "fun" and "bonding" means.

"Intimacy and friendship for a man is built on shared activity, but for women, shared activity is a backdrop for a great conversation," says Les Parrott, a psychology professor at Seattle Pacific University and co-author of several relationship books. "What she wants on date night is a time of intimacy and friendship. He's disappointed because she'll never go to a game or golfing, and it's during shared activities that his spirit is most likely to open up."

Another hurdle to marital bliss: Men and women have different definitions of a "date." When Denver researchers asked 908 people how long it had been since they had been on a date with their spouse, women complained it had been twice as long as men.

"Males and females have different definitions of what a date is," says Markman. "Females' definition is much more planned in advance and the husband puts more effort into it. For a guy, grabbing coffee is a date."

But if you both like baseball, you'll love this: When Markman conducted a study of cities with major league baseball teams, he discovered those cities had a 28 percent lower divorce rate than cities who didn't have teams, but wanted one. So while it may not be a marriage saver, it does offer couples a fun bonding experience.

That said, any type of fun you have together is a self-fulfilling prophecy. Says Thomas Bradbury, co-director of the Marriage and Family Development Laboratory and Relationship Institute at the University of California-Los Angeles: "People in happy relationships generate these activities, and as they generate these activities, it keeps their relationship strong and healthy and fresh."

Do you believe a couple who plays together stays together?