First, let me defend the sisterhood by saying, many, many women don't cheat. Especially when we're in happy relationships. If we're really into a guy, we're loyal-from-first-kiss.
Faithfulness is hardwired into our female circuitry.
Now, the unfortunate exception: Some do. Okay, a lot do: The incidence of extramarital intercourse for women is 25 percent, and the estimate of single women who've cheated is even higher. And if a woman is going to cheat, there are surprisingly specific times when she's likely to do it.
She's Turning 25 or 30 or 35 or . .
Decade and half-decade birthdays trigger navel-gazing-figuratively, and perhaps literally. A woman asks herself, "What have I been doing for the past 5 years?"
The plan: Be there. There are 2 nights when every straight woman wants a man in her bed: New Year's Eve and her birthday. Leave her solo and you're giving her permission—and reason—to cheat. And remember, birthday sex is about the birthday girl. Presents are good, too.
She's Been Promoted
Women like to have projects and goals. When she reaches a milestone-say, in her career—she may start to think, Now what? For her next challenge, she may focus on another big part of her life—say, her relationship. Riding the high of her work success, she'll feel that goals are achievable, and she'll be motivated to get the rest of her life on track.
The plan: Brag about your woman's promotion. Most guys make the mistake of not doing enough to celebrate their girlfriends' accomplishments. When she sees you honoring her, she'll feel as valued by you as she does at work.
She's Moving in with You
Yes, it was probably her idea. But now that you're together 24-7 and sharing every detail of your lives, there's not as great a need to keep the conversation flowing every minute.
She could subconsciously interpret this as meaning that you think she's boring. If there's someone else around who finds her attractive and intriguing-and shows it-she might go for him instead.
And again, with the whole goal thing-now that you've moved in together, she'll be thinking about the next step, such as engagement or marriage.
Face it, most women want marriage, and they want to have children. If you're withholding either or both, you're inviting the risk of her turning to someone else who can make that commitment and give her children."
The plan: Make it clear that you're thinking of living together as a starting point.
She Thinks You've Cheated
Revenge affairs are common. Women have them in an attempt to restore self-esteem and feel desirable again.
It comes down to human nature. She'll want to get even. She won't necessarily go out looking to hook up, but when she's tempted, the fact that you've done it may weaken her self-control.
A survey showed that 86 percent of couples who discussed one partner's affair were still married, compared with 59 percent of couples who barely talked about it.
If you're not cheating, you have one paranoid woman on your hands. She probably has low self-confidence. Your job: Compliment her, sincerely, specifically, and often.
She's Not Getting Enough
Oxytocin, a hormone that plays a central role in our urge to bond, spikes to levels three to five times higher than usual just before orgasm. The hormone is more intense in females than in males, so women develop a stronger sense of bonding through sex.
If the two of you are not having as much sex as you used to, she might interpret this as a sign that you don't find her attractive and that you don't love her. She may seek someone outside the relationship to validate that she's still sexually attractive."
A so-so sex life could also mean you have unresolved problems between you. Research found that 79 percent of cheating women cited dissatisfaction in the marriage as the cause.
The plan: Have more sex.
She's Ready to Bolt
One more reason a woman might cheat: She wants to dump you. Infidelity can break up couples, so she might cheat on purpose as an easy out.
The plan: She sucks—let her go.
If she's the one who doesn't want sex, investigate why. Fix it. Get naked.
The plan: If you are cheating or have cheated before, confess and apologize. You can make her feel better about herself so she won't become vulnerable to these unfounded suspicions.
Talk about the future. Talk about her in your future.
Also, women with fat salaries are more likely to cheat.