In surveys, nearly all American say that fidelity is important in relationships, and that they expect monogamy from their partner. But, people are not always as good at walking the walk as they are at talking the talk. Estimates vary, but surveys say that between 10 and 30% of people will cheat at some point in their lives. Perhaps ironically, many people don't know when they've been cuckolded, even though there are often clear warning signs. Some of the leading tip-offs:

• Your sex life has stalled. If you and your spouse are having a lot less sex than you are used to, they may be getting it somewhere else.
• You don't talk anymore. Many people go out in search of an affair because they feel a lack of intimacy and connection at home. If you and your lover seem to be closing one another out, that could lead to cheating.
• Your lover suddenly starts talking, a lot, about an opposite sex friend or coworker. I've seen this from cheaters in my own life and in the lives of friends. Whether the motivation is guilt or unguarded infatuation, cheaters have a marked tendency to mention the illicit object of their affection more often than is normal. If you're getting tired of hearing about your husband's coworker's ukulele group, this could be a warning sign that something is amiss.
• Your lover has cheated before. While many people who go outside the relationship only ever cheat once, others become serial cheaters. If you are dating or married to someone who has cheated in the past, whether with you or another partner, the chances of them cheating again are higher than if they've never cheated.
• Your lover accuses you of cheating. Cheaters have a tendency to be jealous or suspicious because of their own sketchy behavior. If you are faithful and have given your partner no reason to suspect that anything is up, there is a chance that they're the one who is guilty.

Photo: morgueFile.com