If you want to know how to tell if your wife is having an affair, you might be worried that things have gone terribly wrong in your marriage. Even if you haven't caught your spouse in the act of cheating, you may be able to pick up some clues as to whether she is cheating on you. While none of these signs are definitive proof of infidelity, their appearance in your relationship means it's time to sit down and have a talk about your relationship.

Cell Phone
Check out the cell phone. Cell phones are a great convenience, but they are also great tools for secret communication. If you notice your wife is turning off the cell phone when you come into the room, pay attention. She may be trying to give you her undivided attention, but she may also be trying to hide something. Cell phone bills list each call made as well as the duration of the calls. If there is an unfamiliar number suddenly showing up in the detailed phone bill—especially long calls or calls made only when you and your wife are not together—this could be a sign of an affair.

E-Affair
The computer is another tool used for communicating with a secret lover. If you notice the history on the computer is suddenly being erased after your wife has been on it, keep your guard up. Does she spend a lot of time checking her e-mail? Does she close a browser window when you walk in the room? Behavior changes suggesting that something is being hidden or kept secret are telltale signs all is not well.

She Looks Different
Changes in appearance are another potential sign your wife is having an affair. If her hair and makeup are more important than usual, if she has new clothes—especially lingerie—you haven't seen her wear, she may be wearing them for someone else. Pay attention to her appearance and determine if the changes are for you, for her or for someone new.

None of these clues are evidence your wife is having an affair, but they can definitely be signs something is wrong in your marriage. Try to talk with your wife to see if she has rational explanations for the changes or if the alarms go off in your head when she scrambles for an explanation.