Chris Mower and his high-school sweetheart, Afton, were happy newlyweds. They picnicked in the park, hung out with friends, even took dancing lessons.

Yet before half a year had passed, Mr. Mower developed a rather significant concern: They weren't having enough sex -- and the situation was getting worse by the week.

When Mr. Mower attempted to talk to his wife about the problem, she changed the subject. He tried whispering in her ear. She ignored him. After reading online that women are turned on by men who do housework, he washed the dishes and vacuumed more often. 'It didn't change anything,' says the web designer and food blogger, now 30, who lives in West Jordan, Utah.

Months stretched into years. Mr. Mower tracked their sex life in a notebook he kept in his nightstand. He drew a chart and filled in different-shaped dots to represent various scenarios: He initiated sex but was declined. They planned on sex but didn't follow through. They actually had sex. Mr. Mower says he was rebuffed 95% of the time; his wife says his memory is highly subjective. He became grumpy, gained weight and stopped wanting to come home at night. 'For me to feel good about myself, I needed her to have sex with me,' he says. 'Otherwise I thought she didn't love me.'

The Mowers are unusual in their willingness to speak frankly about a familiar source of marital unhappiness -- differing expectations about sex. They came up with a solution they believe saved their marriage and want to let other couples know.

Remember the scene in 'Annie Hall' where Woody Allen's and Diane Keaton's characters each answer their therapists' questions about how often they have sex? Mr. Allen's Alvy Singer laments, 'Hardly ever. Maybe three times a week.' Annie Hall's complaint? 'Constantly. I'd say three times a week.' Sure, it's funny. Just maybe a little less so if you're a man.

Increasingly, experts believe sex is a more emotional experience for men than for women. Men tend to express feelings with actions, not words. Unlike a lot of women, they probably don't have heart-to-heart chats with everyone from their best friend to the bus driver, and they often limit hugs and physicalaffection to their immediate family.

No wonder they miss sex when it disappears. It's a way for them to be aggressive and manly but also tender and vulnerable. 'For some men, sex may be their primary way of communicating and expressing intimacy,' says Justin Lehmiller, a Harvard University social psychologist who studies sexuality. Taking away sex 'takes away their primaryemotional outlet.'

It is overly simple to assume male sexuality is primarilybiological and that men are constantly looking for a physical outlet, says Esther Perel, a licensed marriage and family therapist in New York City and author of 'Mating in Captivity.' Men, much more than women, relate to a partner through sex, she says, as evidenced by their fear of rejection, concerns about performance and desire to please. 'When a man gets depressed because he's not being touched, it's just like the little boy who stands in his crib and cries to be picked up,' she says. 'He is experiencing emotional deprivation.'

Still, there is a chemicalreaction going on. Physical touch of any kind drives up the brain's oxytocin levels, for both men and women. Orgasm causes the brain to release oxytocin and vasopressin, the 'feel-good' hormones that promote attachment. Men may rely on their partner not just for sex, but for most of their nonsexual touch as well. They tend to have orgasms more frequently than women and to get a testosterone boost from them, which makes them feel better. 'Take sex away and they don't have the chemical stimulants that give them a sense of well-being,' says Helen Fisher, a Rutgers University researchscientist in anthropology.

How much sex is 'normal'? Almost 80% of married couples have sex a few times a month or more: 32% reported having sex two to three times per week; 47% reported having sex a few times per month, according to 'The Social Organization of Sexuality: Sexual Practices in the United States,' a 1994 University of Chicago study considered the most comprehensive in the field.

A study published in the May issue of Social Psychological and Personality Science looked at sexual desire in long-term relationships and concluded that people are better able to sustain desire when they are motivated to meet their partner's sexual needs, even when these needs conflict with their own preferences.

Researchers call it sexual communal strength, and people who rate high in it are willing to engage in sexual activity with their partner even when it doesn't necessarily turn them on. They expect their partner will do the same for them, but it isn't an immediate quid pro quo.

The study followed 44 long-term couples with partners from ages 23 to 60. They answered questions about their sexual communal strength. And they kept diaries for three weeks recording how much sexual desire they had, reasons for having sex (if they did) and other details about satisfaction and feelings of closeness. Four months later, the researchers followed up to see what had changed.

The results indicate that people who rated high in sexual communal strength had more sexual desire and maintained it over the five-month study. People who rated low started out with less desire and it declined. There weren't significant gender differences. 'We think people higher in sexual communal strength are more focused on positive outcomes in their relationship,' says Amy Muise, a postdoctoral fellow at the University of Toronto and lead author of the study. 'They are having sex to enhanceintimacy and feel closer to their partner rather than to please themselves, and this is what leads them to feel higher desire.'

Chris and Afton Mower, who have been married almost 10 years, were raised in the Mormon church and had sex for the first time on their wedding night. Each was excited and stressed. 'We expected sparks and it didn't happen,' says Mr. Mower.

Early in the marriage, Ms. Mower became pregnant and lost the baby. Her libido was diminished, and she was uncomfortable discussing sex with her husband. The couple went months, and once a whole year, without having sex. 'I knew that he felt deprived of intimacy that he really wanted and needed, but all the pressure I felt made me want it less,' recalls Ms. Mower, now 31 and a stay-at-home mom. Mr. Mower recalls, 'Here was an opportunity to get to know my spouse on an intimate level, yet neither of us was opening up.'

Last year, Mr. Mower read a book ('Passionate Marriage,' by David Schnarch) that inspired him to throw out the graphs. He asked his wife to read it, too, and told her they had to work together on a healthy sex life to save their marriage.

'He said, 'It feels like you don't love me' -- and that really, really scared me,' Ms. Mower recalls. 'I decided to raise my game. I let myself feel what I really felt and tried to dig into what had always been buried.' It was a plus, she says, that reading a book about sex made her feel sexy.