Your wife’s patterns and behaviors have changed in small ways. You’re becoming concerned, wondering if she’s having an affair. One or two differences are probably not cause for alarm. When they begin adding up, however, it might be time for a talk. Women are more likely than men to cheat emotionally before they cross a physical line, so you might just be picking up on signals that your marriage has reached a danger zone.

Has your wife's laptop suddenly disappeared when she once left it out in the open? This may be a sign that she is hiding it because she's chatting with someone online. If you access it, you might find out. Other clues include increased computer time after you've gone to bed or erasing her e-mails and internet history.

Like her computer, a rarely seen phone may be a sign that something is going on. There might be something on the device that she doesn’t want you to know about. She might be concealing text messages or a call history that she doesn't want you to see.

Women tend to “trade up” when they cheat, becoming involved with men who are better in their eyes than their husbands. If you’ve got competition and you’re coming up short when compared to him, she might no longer be as tolerant of your less-than-perfect habits. She may seem more annoyed than usual at the behaviors she doesn't like.

If he’s on her mind a lot, your wife might seem more distracted and start forgetting to do things that were second nature to her before. You might have to repeat yourself a few times before she refocuses and acknowledges you. Of course, she may also have a lot on her mind due to work responsibilities or other stresses in her life, too.

If she’s getting emotionally close to someone else, she’ll want him to find her attractive. Watch for a new hairstyle, different makeup, weight loss, a new workout routine and new clothing. She could just be ready for a change, or she may be trying to look her best for someone new.

In order to arrange more time away from home, she might suddenly begin joining organizations that call for frequent “meetings.” If you can’t pin her down on the details of the meetings, you might have a problem. If she's genuinely just taking up a new cause, she'll likely be excited to talk about it and share all the details.

Even if your wife doesn’t suddenly have more commitments outside the home, it might start taking her longer than usual to do the things she's always done. For instance, if she once managed to do the grocery shopping in 45 minutes and now it takes her a few hours, she might be making a stop on her way home.

If your wife’s friends start avoiding you, it might be that they know something you don’t. This is especially true if they previously had a good relationship with you. They might not want to get caught in the middle.

She used to like country music. Suddenly, she’s developed a passion for hip-hop. It's possible that someone else has introduced her to new things that she wants to explore so she can get to know him better.

Women are less likely than men to be able to sustain two sexual relationships at once because sex is often deeply rooted in emotion for them. If she begins to pull away when you touch her and avoids intimacy with you, it could be a sign that your marriage has passed through the danger zone and she is now having an affair.