When we talk about affairs, we often categorize them as emotional, physical, or both. That's helpful to some extent. Yet nowadays, there's another category that we can loosely call the texting affair.
An oversimplified scenario goes like this: Your spouse strikes up an opposite-sex friendship with a person at work, spin or yoga class, the gym, or through your child's school or extra-curricular activities. For some reason, they feel compelled to exchange phone numbers. There's no real need for this, although your spouse tells you that they need to stay in touch because of work or to coordinate fitness class, the kids activities, etc.
Soon, their innocent texting about work or scheduling begins to escalate into personal, evermore intimate texting. Your spouse starts guarding their cellphone and going into the next room to text. They lock their phone, change their password and delete their text history.
For a while, you bite your tongue. After all, nobody wants to be "that wife" or "that husband." You look the other way and pretend not to notice or be bothered. You force yourself to not ask who your spouse is texting and not show how worried or hurt you are. You lay awake and stare at your partner's phone, wishing you could look through it but not wanting to cross that line.
Finally, you crack.
Choosing your words carefully, you ask your partner who he or she is texting. If you already know who it is, you might tell your partner that you are concerned or feeling second-place. Or perhaps you wait until your partner is in the shower and give in to the urge to scroll through his or her phone. Either way, you hear or see something that makes your stomach sink.
More from Debra Macleod:
Here's where anything can happen. Your spouse may downplay the relationship and shrug off your concerns, saying "We're just friends. You have to trust me." Or your spouse may react with an angry, inflated display of wounded indignation by saying, "Oh, so I'm not allowed to have ANY friends?" He or she may turn the situation around so that it's you who finds yourself explaining your behaviour. He or she may make you feel paranoid, jealous, controlling, or pathetic. "You went through my phone! You're crazy. That's private!"
Of course there are spouses who are unreasonably jealous and suspicious, and who behave in controlling ways. Of course there is a reasonable expectation of privacy in marriage. Of course some co-workers and friends need to communicate after-hours. Of course there are unhappy marriages that have deep problems.
But that's not always the case. Suspicions are often warranted. Anger, defensiveness and indignation may be covers for betrayal. Explanations may be just excuses. And all too often, a texting affair steals so much time, energy and emotion from a marriage that a rift forms -- or widens -- between spouses that otherwise would have worked through their marriage troubles.
Unfortunately, there is no formula to determine when texting crosses the line into betrayal. In fact, those who are behaving in inappropriate ways quickly learn how to blur this line so that they can deflect and continue to do what they're doing.
In the end, you must learn to trust your gut.
After all, no one knows your marriage or your spouse better than you do. Texting affairs are the gateway to emotional and physical affairs. Of the infidelity cases I've dealt with in the past several years, the vast majority started out as "innocent" texting between opposite-sex friends or acquaintances. You are not over-reacting by insisting that a spouse end a texting relationship that you feel in your heart is undermining your marriage, and you are not over-reacting by treating it as a form of infidelity.
Blocking the other person's number, keeping communications strictly work-related, being transparent in terms of cell phones and computers (those who have nothing to hide, hide nothing), and working together to improve your own marriage are all reasonable requests.
To prevent and overcome infidelity, couples must learn to build a loving, respectful and protective "fortress" around their marriage, which includes insulating it from the invasive effects of technology. That's something I talk a lot about in my Couples in Crisis book.
Continued inaction or letting the texting continue -- perhaps out of fear of your partner's reaction -- only increases the chances that your partner will begin to see you as a nagging barrier to the exciting and fresh-faced relationship that he or she enjoys via text messages. Texting creates a false sense of intimacy between texters. Within weeks, they may feel that they have formed a deep bond. Too often what begins as a cautious "hi...was thinking of u" turns into "i miss u" and then "can you meet again tomorrow?"
And when it gets to that point, well, the whole thing becomes a lot harder to "delete."
Visit Debra Macleod's private practice at MarriageSOS.com
MORE ON HUFFPOST: