Never let on that you are suspicious of your spouse until you have collected numerous pieces of evidence. If you rush in and confront them after finding one telephone number or text message, you run the risk of alerting them to your suspicions.
Not only will they now stay on their toes, but they will make certain you never, ever have access to your source of information again (i.e.: cell phone, credit card bill, wallet, etc.) To catch a cheating spouse is to behave normally and give them the impression that things are “business as usual”. It is when cheaters are in their comfort zone that they slip up and make crucial mistakes.