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.

FOUR SCENARIOS, FOUR SOLUTIONS

1. The Coasting Couple
Your marriage seems pretty normal. Sure, you aren't having sex as often as before, but nobody's complaining. She doesn't mind your spending a lot of your free time with the guys or in front of the tube, and isn't always asking you to go out with her at night the way she once did. It isn't the passionate romance that it once was, but whose marriage is? All in all, things seem to be running along just fine.

Will she cheat? Possibly. While you may be able to get along "just fine" without romance in your life, many women can't. "If a woman strays, it's usually because she's looking for emotional support she feels she's missing," Lusterman says. "A woman is most likely to cheat because she feels unrequited, unresponded to, unheard. She'll say, `He doesn't know how to talk to me, doesn't pay attention to me-I can talk to my best friend better.' "

The fact that she's stopped asking you to do things with her doesn't mean she doesn't want your company anymore, but that she's given up on you. "If we know anything about why a woman will have affairs, it's that she'll consider it when she perceives her mate is not willing to invest in the relationship, and she feels she has no other option," says Howard J. Markman, Ph.D., a professor of psychology at the University of Denver in Colorado and co-author of Fighting for Your Marriage.

Avoid the horns: "The worst thing a man can do is to take his wife for granted. If you want her to be happy, you need to bring the fun, friendship and sensuality back into your relationship," Markman says. "You should be real companions," adds Lusterman. "Talk, spend time together, and have sex when you're actually awake, not just after everything else is done and you collapse in bed."

2. The Bootie-Based Marriage
Maybe things aren't perfect between you, but she's got nothing to complain about in the bedroom department. You have sex almost every night, often experimenting with new locations, positions and toys. Once in a while she suggests that she'd like to slow down and spend an evening just talking or cuddling. But at least you're sure she has no reason to get the nookie somewhere else.

Will she cheat? The chances are better than you think. While men sometimes sleep with other women because they're looking for a sexual thrill-you know who you are, Stan Lewhorski of Mason, Mich.-that's seldom the reason women have affairs. And while good sex is an important part of marriage, sometimes a woman will feel her husband is focusing on sex too much, says Markman. "It seems to be all about sex, not enough about romanticism."

Avoid the horns: She may want nookie as much as you do, but she still needs reassurance that the sex is an expression of your feelings for each other and not just a way to get your rocks off. "A woman wants to be wooed on a daily basis; she wants her boyfriend or husband to let her know in a way that's meaningful that he loves or cares about her and is attracted to her," says Markman. If she starts to feel she'll never get that romance from you, she may turn to a "friend" who seems to understand her better. And while that outside relationship may or may not ever progress to sex, it's sure to be harmful to your marriage.