Story highlights People's bodies and desires change over time, experts say

Couples need to talk honestly about sex before tying the knot, Ian Kerner says

A therapist can help get the conversation started, Kerner says

Most couples tying the knot don't want to wait until the honeymoon to know if things are going to work in the bedroom, and would agree that having sex before marriage is an important way to establish if there's a basic level of sexual compatibility.

But -- without getting into the moral pros and cons of premarital sex -- that may not always be the case.

"Just because you have good sex, and a lot of it, before marriage doesn't mean it will be that way for your entire life," says social psychologist Justin Lehmiller

"Our bodies and desires naturally change over time in response to both age and major life events, such as having children, and these changes don't affect everyone in the same way. This means that one partner's sexual needs and wants often change at a much faster rate than the other's, resulting in discrepancies that can precipitate conflict, adultery and divorce."

You can't judge the rest of your sex life by your current experiences, especially if you've had a whirlwind romance. In the beginning of your relationship, you're both under the influence of a potent biochemical cocktail of infatuation hormones.

Ian Kerner

"A person's inherent need for sensation is not necessarily obvious in the early stages of a relationship, when love itself is a novelty and carries its own thrills," says Marvin Zuckerman , a professor at the University of Delaware whose research involves sensation-seeking. "It's when the sex becomes routine that problems occur."

That's why I recommend that couples talk openly and honestly about sex -- whether or not they're already having it -- before they walk down the aisle.

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"As a newlywed sex educator, I've been surprised at how much marriage has changed our sex life in ways I would never have anticipated," says Emily Nagoski , author of the book " A Scientific Guide to Successful Relationships ."

"Based on my experience, I think that the best thing a couple can do is talk through a wide range of hypothetical scenarios -- what if one person's interest in sex changes a lot, either increase or decrease? What if one of you gets cancer or is in a car accident and loses sensation below the waist? These 'what ifs' aren't about having a plan for every contingency; they're about practicing your collaborative problem-solving skills."

But talking about sex isn't always easy, even for couples who plan to share everything with each other. Most of us have had some sex education somewhere in the past, but nobody ever taught us how to have a constructive conversation with a partner about the sex we're having.

"When you're not able to openly talk about sexual preferences with your partner, those bedroom problems will resurface in other aspects of their relationship, and can lead to misdirected frustration," says Patty Brisben , a sex education advocate and entrepreneur.

For those couples who are too inhibited to get this conversation started on their own, a trip to a marriage and family therapist should be a priority.

"Premarital counseling provides a safe space for couples to discuss their sexual hopes, fears and expectations," says Ami Bhalodkar , a New York marriage and family therapist. "Counselors can help couples initiate and engage in conversations about sex in ways that are tailored to their particular style of communication, cultural/religious background and overall level of comfort and emotional safety -- be it through journaling, making art, reflecting on poetry and music, playing a card game or participating in a speaker/listener dialogue.

"Regardless of the methods used, once couples have broken the silence around this issue, they report feeling incredibly relieved and more secure and optimistic about their sexual future together."

So keep an eye on the long view. "This person is going to be sleeping next to you every night for the rest of your lives -- decades, hopefully," Nagoski says.

"Without making a little effort to try new things, it can get routine, fast. Trying new things together isn't really about the things you try, it's about the sense of adventure as you explore together."

By talking about your concerns and expectations now, you can build a strong foundation for a healthy, happy sex life -- till death do you part.