What drives people to infidelity may surprise you. Selfless devotion is at the top of the list.

If you were worried that your spouse might stray, what would you do to prevent it? Maybe your knee-jerk response is: “I’d lose 20 pounds and upgrade my wardrobe.” Or, “I would shower my spouse with expensive gifts.” Or, “I would be extra attentive to my spouse so he would realize how good he has it.” If your answer resembled any of those above, bad news: You’re on the wrong track. You’ve bought into a common misconception about what causes affairs in the first place.

Most individuals assume that people have affairs with someone more attractive, sexier or richer than their spouse. Despite the clichés, that’s not what infidelity is about. People who cheat generally choose someone busier and more goal-oriented than their current partner. Someone more interesting, in other words.

The harsh truth is that when one spouse strays, it’s probably because the other spouse has become, well… boring. Here are a few warning signs that your marriage may be ripe for an affair:

You don’t challenge each other. Healthy marriages require a mutual willingness to challenge and be challenged. An “Oh, I’ll let the little woman do whatever makes her happy” attitude is condescending and harmful. If your partner lounges around in his bathrobe watching TV every day and you say nothing, then you’re not invested in his well-being. Maybe he’s depressed. Maybe he’s sick. Maybe he’s succumbing to laziness. Regardless, the message that he gets loud and clear from your silence is that you don’t care. Not only do you have the right to make reasonable demands on your partner, you have the obligation to do so.

You and your partner have become an amoeba. If you and your spouse do everything together, something’s wrong. If your partner is not allowed to have a life of his own, he will eventually become resentful. Similarly, if you’re over-interested in his life, wanting to know or be involved in every detail, he will feel intruded upon and smothered. True intimacy requires two people having independent lives, not two people living through each other. The best marriages are low-maintenance marriages.

One person selflessly lives for the other. I like to tell the story of Bernard, a heart surgeon, and Stacy, the wife who selflessly devoted herself to him. She supported him through medical school. She stayed home and raised their kids. She prepared gourmet meals for him, often complete with heart-shaped ice cubes. And one day Bernard left Stacy for a disheveled photojournalist, two years his senior, who chastised him for stealing a cab she’d just hailed. Why? Because the photojournalist was interesting. Selfless devotion is boring. Bernard could have hired a housekeeper and a caterer. Gratitude for services rendered is no replacement for a stimulating partner. And by failing to cultivate a life of her own, Stacy deprived Bernard of that.

Everything centers on your children. Don’t succumb to the temptation to make your kids the center of the universe. For too many parents, running kids to and from soccer practice, dance lessons and weekend parties becomes an insidious dance of intimacy avoidance. When you are reduced to being little more than an appointment secretary or a taxicab for your children, there’s precious little time to develop an identity, a life of your own. Remember, children are temporary. One day they will grow up and leave and your marriage will still be there. More to the point, you’ll still be there. So devote at least as much energy to your personal growth as you do to the social life of your kids.

You don’t have meaningful conversations with your spouse. Quality communication is the heart of intimacy. (And you thought it was sex!) If you’re confused about what constitutes a high-intimacy dialogue, here’s a clue: It centers on feelings, not information. Instead of merely reporting to your partner what happened to you that day, tell him how it made you feel. Even if you have only ten minutes a day to talk to him, make those ten minutes count.

Interestingly, most of these warning signs are variations on a common theme: abandonment. If you don’t care enough to become an interesting partner, if you don’t challenge your spouse to “be all he can be,” if you fail to connect with your partner emotionally, you might as well be a disinterested roommate. Abandoning your spouse is the first step to checking out of the relationship.

So what can you do to affair-proof your marriage? The answer can be summed up in three little words: Get a life.

Set goals and work toward them. Immerse yourself in a career or activity that interests you. Don’t just hop from one random activity to another. Have a vision of what you want your life to be and do something every day in pursuit of that vision. Take some risks. And challenge your spouse to do the same. Even if it causes some temporary discomfort, remember that a healthy marriage isn’t about comfort zones and status quos. If you settle for comfort, your marriage will die.

There’s one other point I would make. Create a rich, rewarding life for yourself and if your spouse did have an affair and ultimately left you, you would be well-equipped to cope. Interesting people just have more resources, be they money, social connections or potential new romantic partners. There are no guarantees in marriage. The only person you can count on to always be there is you. Being abandoned by a spouse is far preferable to abandoning yourself.

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