You can't even remember when you first began to notice that things weren't quite right between you and your girlfriend or wife. It wasn't as though she made a searing proclamation during an argument, and you certainly didn't catch her red-handed with another man. But you've been noticing “little things” about her behavior: She looks panicked when her phone rings or a text message arrives. She doesn't make an effort to spend time alone with you. And she seems oddly preoccupied or distracted when you do. As hard as you try to push the thought from your mind, it creeps up on you anyway: She's cheating; I feel it.

Aggrieved partners often say that it was their gut instinct about the little things that got their attention and caused them to pay attention to signs of infidelity. At this point, you may be tempted to search for evidence in your loved one's phone, computer or laptop. But chances are that even the mere thought of doing so pains you because it's the cruelest of ironies: To confirm that your girlfriend or wife is violating your trust, you have to violate hers. Actually, you don't have to. (And besides, what if your suspicions are wrong? If you get caught, imagine the harm it might do to your relationship.)

While no two women are the same, psychologists say that women tend to exhibit five telltale signs that they're cheating on their boyfriend or husband. Taken individually, no one sign may seem troublesome. But read the entire list to see how these signs paint a picture that you probably shouldn't ignore.

1. Unfaithful women often change or become more focused on their appearance. At the beginning of a relationship, both men and women tend to “step up” in a number of ways, beginning with how they groom and dress themselves. Women can be particularly fastidious by purchasing more feminine clothing, wearing more jewelry and makeup, styling their hair differently, or vowing to slim down or lose weight.
   
   
2. Unfaithful women often spend more time at work – or at least say they do. If your girlfriend or wife does not hold a job outside the home, she may be looking for ways to spend time away from it. She may say she is going shopping. She may say she is meeting a girlfriend for coffee. Or she may say she is going to join a new hobby or political group in town. Whatever the story, her usual schedule or routine has changed – because something is going on to change it.
   
   
3. Unfaithful women make stronger bids for privacy. In trusting relationships, people should have nothing to hide; women who are seeing someone else do. If your girlfriend or wife once left her cellphone on the counter and is now concealing it, or once left her computer on and is now guarding “her turf,” she may be unwittingly signaling that she is communicating with someone she shouldn't. A particularly gut-wrenching sign: You hear her talking to someone as you walk into a room, but she hangs up abruptly when she sees or hears you approaching.
   
   
4. Unfaithful women are suddenly, always busy. Your girlfriend or wife may try to throw you off “the scent,” but women who cheat are more transparent than they may think. They're usually not interested in splitting their time between two men; they're more likely to focus on one. In switching their focus, they spend less time and take less interest in their primary partner.
   
   
5. Unfaithful women withdraw from physical contact. It's not just sex that unfaithful women tend to withhold; it's any sign of physical affection, including hugging, kissing and cuddling. For men, this can be a crushing blow to the ego – and the final straw in their quest to stay silent as they assess the signs.

Taken together, these signs create a hurtful picture. But it's pointless for people to advise “keeping a cooler head” when it's not their world that feels like it's crashing down around them. So when you're able, talk with your girlfriend or wife about your fears. If she confesses to infidelity, it may help to know that many couples who are committed to saving their relationship successfully do so, often after couples therapy. Sometimes, these couples even grow closer, thereby closing a torturous chapter in their lives on a fulfilling note.