It's about 7 p.m., and I'm engrossed in a video of Katy and Mark, a married 20-something couple, having sex.

I don't like what I see.

Katy energetically climbs on top of Mark and works her way toward orgasm while Mark might as well be lying in a coffin. Katy grabs Mark's shoulders; his hands remain virtually motionless at his sides. Her moans grow more insistent; whatever noise he might be making isn't even loud enough for the microphone to pick up.

No, I'm not watching porn (though if it were porn, it would be disastrous). Mark and Katy, who have been together since they were teenagers, are one of the dozens of couples who come to me seeking help with their love lives. Mark claims he wants "rampant" sex with his wife. But from what I see, he needs to look up the word.

I help couples like Mark and Katy by watching videos of them having sex (and interacting outside of the bedroom), then analyzing what I see. These aren't Paris Hilton-style tapes; they're videos that force couples to take an uncensored look at how they treat each other. The nuances in body language they reveal — a lack of eye contact here, a perfunctory hug there — hint at much deeper issues in the relationship.

For every couple I've seen on tape, the camera illuminates the contradiction between what they think they do and what they actually do. While Mark insisted he wanted his sex life to sizzle, you wouldn't know it. Even his position — flat on his back — reflected his passiveness. When we noted this on the footage, Mark was floored.

For many, the thought of a camera in the bedroom is at best adventurous, at worst perverted. But for those who wonder, What kind of person would agree to have their sex life videotaped and analyzed?, I say, "Well, what would the cameras reveal if they were filming you?"

Think of the camera as the mirror you've never looked into. After Katy viewed a bungled bedroom moment — she flung Mark's arm away when he tried to cuddle with her on the bed — we paused the tape. I told her I had a secret, then whispered, "Men have feelings, too." She started bawling, and we had to give her a few minutes to collect herself. She had no idea she was confusing her husband's attempt at affection with a quest to get in her pants.

This confusion between affection and sex surfaces often, and it's a multilayered issue. First, if someone isn't in the mood for sex and assumes her partner is, she usually chooses the wrong way to reject him (like Katy did). Second, this "all or nothing" mentality reinforces the idea that physical contact must be sexual. On film, these issues become all too clear.

Another couple, Bina and Mark, struggled with a related issue. Bina, whose sex drive outpaced her boyfriend's, constantly pressured him for romps. What she didn't know — until she saw herself clinging all over Mark — is that she was craving simple body-to-body contact as much as a good shag.

Bina's preoccupation with sex highlights a similar line of thought among many couples: that simply being a good lover can carry the rest of the relationship. You can brag all you want about how well you go down on your boyfriend, but if you act like a bitch all the time, he's probably thinking about somebody else while you're doing it.

If you want your sex life to bloom, you have to pay more attention to tilling the soil than planting the flower. That means making your partner feel good about you, himself or herself, and your relationship — the stuff we always hear but don't pay much attention to. Out-of-bed footage and video diaries reinforce that what happens at 8 a.m. clearly affects what happens at 8 p.m.

Paul, a feisty 23-year-old engaged to Sally-Ann, who is 11 years older, was downright embarrassed to watch himself constantly brandishing his penis and begging to be serviced by his fiancée, even if she was wiped out after doing all the housework. Almost as quickly as he could zip up his pants, Paul went about changing his behavior. He signed up for his share of the housework — and actually did it — and stopped acting like a prepubescent. As a result, Sally-Ann stopped using sex as a bartering tool and began to see it as a mutually enjoyable act.

Gone was the sexual power struggle that plagues so many couples. While both partners are the gatekeepers of sex, the one who says no and keeps the gate shut has the power. The danger in amassing that power — and doling out sex like cookies, as one member of a couple often does — is that it inevitably generates a power-resentment loop. The more you say no, the angrier, more frustrated your partner gets — and the angrier, more frustrated your partner gets, the more you want to say no.

Kelly and Sean, married for less than a month, had a different power dynamic. Kelly clearly had the upper hand in the marriage, partying with her friends several nights a week and whining for Sean to do things like bring her a glass of water when they were in bed — generally treating him like a doormat. Not surprisingly, her dominance extended into their sex life.

The solution ended up being several bans for the couple. Kelly wasn't allowed to talk on her cell phone after 9 p.m. (a huge sacrifice, considering she'd brought the damn thing to bed on their honeymoon) or initiate sex. Sean, on the other hand, was banned from doing Kelly any favors unless she reciprocated. The results were phenomenal: Kelly began to respect Sean, and he went from submissive to sure of himself. Their sex life soared, and their follow-up footage — with Kelly looking smitten and Sean confident — was some of the most touching we taped.

Of course, on-the-mark advice doesn't always save couples. Sean and Safia sparked in their sex life but noticed they spent most of their free time watching television. After they turned it off, they discovered they had nearly nothing in common and broke up.

If the thought of a camera watching you in bed makes you cringe, I challenge you to ask yourself why. If it's because you view sex as a private act, that's one thing. But if it's because you're uncomfortable with what the footage might reveal — your selfishness? his passivity? hours of the two of you sleeping? — then perhaps you need to take a harder look at your relationship. With or without a camera.

Michael Alvear is a relationship and sex expert, a syndicated columnist, and cohost of The Sex Inspectors on HBO.

Want Michael Alvear to help your sex life?

His video-based sex advice will be available online starting in July. For $100, you can join, submit Web video footage of you and your partner in and out of the bedroom, and get his take on how to improve your relationship. For more information on how to participate, go to blabbermash.com

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