There are many ways to deceive a spouse: physically, emotionally, and financially.
Now, a new form of betrayal has been added to the list - it's called 'micro-cheating.'
The subtle deception could be just as harmful as a full-fledged affair.
"Micro-cheating refers to a small series of actions that don't quite meet the definition for cheating," psychologist, Dr. Barbara Greenberg explained to WCBS-TV.
Frequent confiding in someone outside of a marriage might be considered micro-cheating.
The micro-cheater might rationalize this as just talking to a friend, but Greenberg said it's actually a very intimate act.
"The difference between friendship and micro-cheating is friendships are not usually kept secret, but when you're talking to somebody and keeping it secret, that starts to meet the definition of micro-cheating," Greenberg said.
Other examples of micro-cheating include calling or texting a friend for information or advice on an issue that could easily be found online, giving an attractive waitress or waiter an excessively large tip, or purposefully neglecting to mention a significant other in a conversation so as to appear single.
"There's two different ways to look at it. On the one hand, a person might be engaging in what I like to call 'safe excitement.' Sometimes the primary relationship gets a little routine, or they may simply be testing the waters to see if other people still find them attractive," Greenberg said.
"To a person who is micro-cheating, sit down and think, what purpose is micro-cheating serving you? Are you unhappy in your current relationship or is this just a temporary indiscretion?" Greenberg said.
If you think you're being micro-cheated on, experts say it's best to address it early, before the relationship progresses even more.