How to Tell If Your Wife or Girlfriend Will Cheat, and How to Prevent It Beware the warning signs and stop her before she strays.

3. The Working Wife
She's gone back to school or work and is meeting lots of new, interesting people, including plenty of men. At night, she talks about the new things she's learning and experiencing. Finally, you tell her that the idea of her being around so many men during the day is starting to bug you. She assures you that you have nothing to worry about.

Will she cheat? Probably not. While work or school would give her more opportunity to find someone else if she were actively looking, it's more likely she's concentrating on her career or academic responsibilities, Markman says. "The fact that she's around other men won't mean much if she's happy in her relationship with you," he adds. And if she's discussing her daily activities with you, it shows she wants to bring her new experiences into the relationship rather than use them to provide an escape from it.

Avoid the horns: Of course, Markman adds, it's natural for you to worry when she enters a new stage in her life, but discussing your fears with her rather than turning into a jealous jerk is likely to make your marriage stronger. In fact, she'll probably be so happy that you actually initiated a relationship talk on your own, you'll get brownie points for days.

4. The Restless Relationship
Since the baby was born a couple of years ago, you haven't been very happy at home. Your wife still hasn't taken off all her pregnancy weight, and you can't remember the last time the two of you had sex on a weekday. You're working your butt off to provide for everyone, and yet she still complains that you aren't helping out enough around the house. In fact, other women are starting to look pretty good to you; there's a certain young associate you've been flirting with at work, and who knows where that will lead?

Will she cheat? She damn well might. A tough period in a relationship doesn't mean she's going to have an affair, but it becomes more likely if you go out looking to meet your own needs and no longer seem to care about hers.

"Every marriage goes into the doldrums at some time," Lusterman says. "It may be when a child is born and the man feels left out of things, or the woman feels he isn't participating enough. And it can happen with a dual-occupation couple if there isn't enough leisure time together, or when a woman becomes more specialized in child-rearing and there's more burden on the man to produce income. If you're sensitive to that, you can talk about it. Unfortunately, often a woman will try to talk about it but feels unheard."

Avoid the horns: If you respond to your own marital dissatisfaction by pulling away rather than dealing, it's likely that she will too, and neither of you will get what you want. The fact that you yourself are tomcatting around should be a warning sign that you probably don't have the first clue about what she's doing either, Lusterman says. If you're behaving this way, then it's time to stand back, have a good look at the issues you're hiding from, and put your energy into your marriage instead of into seducing the next ex-Mrs. You.