11/04/2014 10:57 am ET Updated Jan 04, 2015

The One Thing That Will Kill Your Sex Life

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You cannot get lazy. In my years as a relationship consultant, excavating the world of sex and dating, I've found laziness is the number one reason couples quit having sex. Over time, this can be a relationship killer, no matter how strong the two of you start out.

Few excuses for not having sex are worth the long-term price.

Of course, there are real life interruptions that take their toll on sex. Health, money issues, betrayal, underlying incompatibility to start out with... nothing will help your sex life together as time drags on if you start out on this weak footing.

If there is friction between the two of you that's new, however, the first thing to check is the last time you had satisfying sex with each other. People would be amazed at how the simple act of getting laid can make whatever you were mad about disappear. It's that way in my life, as well as in the lives of the hundreds of people I have talked to in my work as a relationship consultant.

The problems that arise in relationships around sex are often over-analyzed. To me, it boils down to being honest with yourself about your own laziness when it comes to your personal pleasure. Sometimes, you've just got to jump in, commit to getting naked with your partner and just have sex.

Sounds easy, but how do you do it? I'm going to be blunt here, so if you need a touchy, feely approach to getting your relationship sex life revved up, this likely won't satisfy you.

To me, having sex once a week is the minimum for a successful relationship. Pick a day and do whatever it takes to get it done.

If you're not having sex regularly in your relationship because of something physical that's gone awry, it's your responsibility to see a doctor and find out what's wrong. This includes erectile dysfunction, constipation, drinking or eating too much or using drugs inappropriately, hormone issues (which for women of a certain age can play havoc with your libido and also your ability to orgasm). Pain during intercourse, whatever the source, it's your job to fix it, because in a partnership, each person has to be present physically and healthy.

If you've checked out of your relationship because you've become dissatisfied with your own life or your career, do something about it. Being lazy sure won't fix it.

Next, you've got to be able to talk openly with your partner. It takes work to do this. People think there's some magic equation to having great sex and opening up with your partner. Just blurt out what you want from her and don't make him guess what gets you off.

Don't be afraid to tap your own personal fantasies to get yourself aroused, which applies to both sexes. Sometimes life interrupts, but it's just a horrible idea to put off sex another day, let alone another week.

Sometimes, especially when you're both leading busy lives, it's just sex. What I call service sex, which means you both want to get down, dirty and gratified. Women can get there, too, especially with toys. Today's sex toy industry offers a wide variety of all sorts of wonderful gadgets to get you off. Use them, especially when it's a sex date and the goal is to get naked and satisfy each other.

Sex doesn't require romance every time.

It does demand that you look at sex as fun!

You've got to want to be together in bed, which begins with having your bedroom be a place that's meant for physical romping. The primary purpose of a bedroom is to be an adult playroom. Keep a tray on your bedside table with lotions, creams, etc. to remind you of sex as a primary place in your relationship. Never, ever, ever talk about work, especially money, or anything else in your bedroom. Fights stop at the door.

And speaking of arguments... in a long-term relationship, you can always continue the fight after having sex. You might find you're both more rational after a good endorphin rush.

Now I realize some of this may seem foreign to you, sound easy and even flippant. But sex is like eating; you need it to be healthy, strong and vibrant. It's a mood elevator. It's great for your self-esteem.

It's just sex.

...and in a long-term relationship, after the newness has worn off, it gets down to doing it. Regularly.

Each person in the relationship must come to appreciate what sex means to their partner, but also your lives together. If your partner is not having sex with you, eventually, someone else will enter the picture or other habits will invade that wrench intimacy from a relationship.

We are all sexual people, even when we go through times where we don't feel sexy, or when our partner doesn't do it for us. These times are temporary. If you go through a period when you don't want to have sex, there are ways to be present with your partner so she or he can still get theirs.

As time goes by our bodies change, so how we have sex has to, too. But sex is always worth it.

Sex can act as a magic elixir if you commit to the adventure of knowing your own body and that of your partner's. There is nothing that cements a relationship tighter than sex, which is the one thing that separates your relationship from your friendships. Too often, people forget this.

Don't get lazy. Stop the excuses.

It's just sex and it's wonderful for you both.

Taylor Marsh is a speaker and the author of The Hillary Effect on Clinton's rise and the 2008 election. Her third book on relationships is titled The Sexual Education of a Beauty Queen -- Relationship Secrets From the Trenches.