Are you feeling suspicious about your partner’s new “friend?” If you’re like most people, it’s easy to question yourself and worry you’re being paranoid. (Especially if your partner vehemently denies any wrongdoing).

However, just as a good detective can lift unseen prints from the scene of a crime, you too have access to subtle clues that might mean trouble. In fact, there is one very distinct sign that may indicate the presence of an affair: You can feel your partner withdrawing emotionally.

The dead-giveaway fingerprint of an affair — emotional or otherwise — is when one person suddenly stops being emotionally engaged with their partner. This can take many forms.

* Does your spouse suddenly feel more contemptuous of you, or like they’re silently comparing you to someone else?
* Are they suddenly less interested in sex?
* Are they recently more invested in other parts of their life (going back to school, their job, a new social club) that you can’t be a part of, and that they don’t want to talk about with you?
* Are there things that they used to fight with you about, but now they just sort of roll their eyes at you and leave the room instead?

Here’s why these signs can point to an affair:

A very famous family therapist by the name of Murray Bowen first described the phenomena of “triangulation” in his family systems research in the 60s and 70s. He observed a common pattern where

1. Person A has a problem with person B
2. Person A avoids solving the problem with person B
3. Person A tells Person C all about it instead.

Even though nothing changes with person B, person A feels better after sharing with person C.

This is highly problematic for a relationship. Not only does Person B not have the opportunity to work on things with Person A, but Person C feels like an easy, friendly oasis of compassion and caring in comparison.

Person C doesn’t make demands on Person A. In fact, Person C thinks that person A is wonderful, and entirely justified in their negative assessment of person B.

It quickly feels less important for Person A to resolve things with Person B because their emotional needs are being met by Person C. Person C is now their confidant, their supporter, and their friend. Person B has been demoted to the emotional status of an annoying roommate that must be grudgingly tolerated.

An emotional affair has been born.

Sadly for person B, they often don’t realize that this shift has happened. In fact, they are more likely feel that things are suddenly getting better in their marriage even though nothing has changed. Person A isn’t fighting with them anymore, and might seem more content. Maybe they don’t talk as much or Person A is always busy, but at least you’re peacefully coexisting, right?

Wrong. If your partner has stopped participating in a meaningful way, your marriage is in trouble. If they are no longer interested in expending the energy and effort in attempting to resolve problems with you, it can mean they’ve either solved the problem elsewhere or stopped believing that positive change is possible. Either can be the death rattle of a marriage.

Furthermore, emotional affairs are essentially the first stage of a serious-for-real capital "A" Affair, with clandestine sex, escape fantasies, and all. Attractive strangers don’t typically encounter each other in a hotel elevator and start ripping each other’s clothes off. Fluttery sparkle feelings lead to texts, to coffee, and to lunch before, over time, they progress to make-out attacks. This must be nipped in the bud.