Here are some tried and tested clues or “signs” that cheaters most often exhibit

• Your spouse, girlfriend, boyfriend, fiance/fiancee, or significant other:
•  Has a history or prior instance of infidelity. This falls under the “if it has happened before it is likely to happen again” rule. Those men and women who have cheated once will generally relapse.
• Has been spending a lot of time lately working out, in the tanning salon, or beauty salon cultivating their appearance.
• Seems to act more cold and/or distant and inconsiderate of your feelings.
• Is spending a lot of time on the cell phone away from you out of ear-shot. They also may leave the house or room to talk on their cell phone in a sudden manner.
• Suddenly hangs up the phone or acts really odd when you walk in the room. They tell you they were on the phone with someone at work, wrong number, etc.
• Hides their cell phone bill from you or is very protective of the bill when it arrives in the mail.
• Secretly purchased a new cell phone.
• Receives suspicious voicemail messages.
• Has recently started using phone cards.
• Seems to never answer their cell or home phone in a timely manner when you try to reach them by phone during the day. If they do answer, they seem to be very evasive with you and not truthful about their current whereabouts. They may tell you that they have been having cell phone problems.
• Started using a password on their cell phone.
• Keeps their cell phone with them on the time and won’t let the phone out of their sight.
• Is lying to you about insignificant things.
• Has suddenly stopped complaining about things in their relationship with you that have bothered them in the past.
• Has a secret P. O. Box that they are hiding from you.
• Has found reasons not to attend family or holiday gatherings.
• Started having their laundry handled independently.
• Seems to have started acting in a paranoid manner. This may include such behavior as your spouse, girlfriend, boyfriend, fiance or fiancee inquiring if you have been “snooping” on them.
• Is consistently washing their vehicle and keeping it meticulously cleaned out.
• Has a secret banking account that they are keeping you unaware of.
• Exhibits defensive behavior in normal conversations with you.
• Inquires about your daily/weekly schedule more often than usual.
• Has developed a sudden interest in a new hobby or sport.
• Spends a lot of time on the computer e-mailing or instant messaging at odd times of the night. Statistics indicate that 31% of people have had an online conversation that has led to real-time sex. Approximately 70% of time on-line is spent in chat rooms or sending e-mail; of these interactions, the vast majority are romantic in nature. 38% of people have engaged in explicit online sexual conversation and 50% of people have made phone contact with someone they chatted with online.
• Is frequently deleting e-mail messages.
• Is being very secretive and protective of the activity on their home computer. This may be while they are in chat rooms or on the internet.
• Tells you “I just need my space” when confronted regarding their suspicious behavior.
• Ignores or deflects your romantic/sexual advances.
• Begins losing interest in romantic gestures like giving you gifts, cards, or flowers. This may also work in reverse due to their guilt over their indiscretions.
• Speaks to you often regarding a new coworker. This may be a new secretary, manager, or intern that your partner spends a lot of time alone at work or on the road with.
• Has received a new promotion and is spending more time out of town than usual.
• Additional Signs or Red Flags that  you may have discovered:
• You receive hang up calls at home in the middle of the night or at odd times of the day
• You start receiving a lot of wrong number calls at home.
• You discover unfamiliar numbers stored or dialed on their cell phone
• You notice a new cologne/ perfume or sexy clothing in their vehicle.
• You discover unfamiliar earrings or jewelry show up in their vehicle or somewhere in your home.
• You notice unfamiliar hairs (a different color or length than you or theirs) in their vehicle, on their clothing, or in your home.
• You notice the odor of cigarette smoke on your non-smoking partners clothing or in their vehicle. This is usually from the partner meeting with their new partner in bars or being around that new lover who smokes.You notice unexplained mileage changes on the odometer of their vehicle.
• You notice credit card receipts from locations they have visited that seem questionable.
• You notice they seem distant and distracted most of the time and not very interested in you in a sexual manner.
• Friends or acquaintances start informing you that they saw your spouse, girlfriend, boyfriend, fiance/fiancee, or significant other out somewhere with some unfamiliar individual. Most times, friends, family, or acquaintances will find out about the cheating way before you do.
• You notice changes in you and your partners sex life. This could be more activity or less activity. New or experimental sexual techniques and acts could be involved, wanting to experience with toys or role playing, where you never did this before.
• You notice a change in contraception or pregnancy prevention methods between you and your partner. This can include the sudden introduction of condoms by your partner to prevent the possible passing of any sexually transmitted diseases.
• You notice your partner departing from home to work earlier than usual on a consistent basis. Confidence levels seem to have risen considerably for no apparent reason. They are spending less time at home and more time “at the office” or “working late”. This would be unaccounted time.

At the beginning of an affair the mate that is cheating is more attentive to his spouse. This is due to guilt that the cheater may be feeling at the time.

After the affair has been going on for a while the person cheating seems to find fault with the person he/she may be living with to try to justify the affair in their mind.