An "emotional affair" is an affair which excludes physical intimacy, and is usually based on emotional intimacy. An emotional affair can also be referred to as an affair of the heart. It is a phenomenon that is not limited to married couples, affecting people in serious relationships of every type. An emotional affair may begin innocently as a friendship with a person outside the relationship. Over time, the partner becomes infatuated, obsessed in some cases, with this friend - and eventually tries to become friendlier, spending more time with him or her at the cost of the relationship that person is already in. Where one partner is in a committed monogamous relationship, irrespective of whether marriage is planned or not, and irrespective of if the couple is already married or not, an emotional affair can be considered a type of chaste nonmonogamy without consummation. When the affair breaches an agreement in the monogamous relationship of one of the partners to the affair, the term infidelity may be more apt.
It is important to distinguish between an emotional affair, a healthy friendship that does not risk the present relationship, and signs of a failing relationship that have nothing to do with emotional affairs to begin with. For a heterosexual person, a relationship with a member of the opposite gender in of itself can be healthy and is not necessarily an emotional affair. If the relationship in question was poor and tenuous to begin, and problems were occurring before the extraneous relationship was formed, the term "emotional affair" is less applicable - the relationship may instead be suffering from a Relational disorder.
An emotional affair can be defined as:
"A relationship between a person and someone other than (their) spouse (or lover) that has an impact on the level of intimacy, emotional distance and overall dynamic balance in the marriage. The role of an affair is to create emotional distance in the marriage."
In this view, neither sexual intercourse nor physical affection is necessary to impact the committed relationship(s) of those involved in the affair. It is theorized that an emotional affair can injure a committed relationship more than a one night stand or other casual sexual encounters.
Incidence and prevalence
Research by Glass & Wright found that men's extramarital relationships were more sexual and women's more emotional. For both genders, sexual and emotional extramarital involvement occurred in those with the greatest marital dissatisfaction.
Chaste and emotionally intimate affairs tend to be more common than sexually intimate affairs. Shirley Glass in her study, reported in 'Not Just Friends'  44% of husbands and 57% of wives indicated that in their affair they had a strong emotional involvement to the other person without intercourse.
In University of Chicago surveys conducted by NORC  between 1990 and 2002, 27% of people who reported being happy in marriage admitted to having an extramarital affair. The meaning and definition of what infidelity constitutes often varies depending on the person asked. Sexual feelings in an emotional affair are necessarily denied to maintain the illusion that it is just a special friendship. Affair surveys are unlikely to explore what is denied. Many people in affair surveys are not honest with themselves nor with the interviewer.
This type of affair is often characterized by:
- Inappropriate emotional intimacy. The partner being unfaithful may spend inappropriate or excessive time with someone of the opposite or same gender (time not shared with the other partner). He or she may confide more in their new “friend” than in their partner and may share more intimate emotional feelings and secrets with their new partner than with their existing spouse. Any time that an individual invests more emotionally into a relationship with someone besides their partner the existing partnership may suffer.
- Deception and secrecy. Those involved may not tell their partners about the amount of time they spend with each other. An individual involved in this type of affair may, for example, tell his or her spouse that they are doing other activities when they are really meeting with someone else. Or the unfaithful spouse may exclude any mention of the other person while discussing the day’s activities to conceal the rendezvous. Even if no physical intimacy occurs, the deception shows that those involved believe they are doing something wrong that undermines the existing relationship. In other words, if there was really no harm in meeting with a friend, both parties would feel comfortable telling their partners the truth about where they are meeting and what they are discussing.
- Increased fighting. When a person becomes emotionally involved with a third party, they will almost without fail begin to discount their primary partner, if not view the new person as all good and their committed partner as all bad. This person may blame their interest in the third party on their committed partner, which will lead to increased fighting and strain on the relationship.
- Sexual and emotional chemistry. Sexual and emotional chemistry can present itself based on a physical attraction one might feel for another person. In addition, it can also be related to an increase in dopamine, a hormone that produces feelings of pleasure, and norepinephrine, which is similar to adrenaline and causes an increase in excitement. This may or may not lead to physical intimacy, however, if nurtured it may present itself. The time between the first meeting and a first kiss can often be very lengthy, but the time between the first kiss and sexual intercourse may be very short. In most of these affairs, however, an unspoken attraction exists. A partner may spend extra time getting ready before seeing this "friend" or may buy new clothing or change their appearance to seem attractive to them. They may obsess anticipating phone calls, emails or text messages
- Denial. Denial of the attraction and limerance felt may be exhibited by the cheating partner, but a similar denial and minimisation may also be defensively deployed by the excluded partner as well, to avoid confrontation.
In Casanova's Chinese Restaurant, the composer Hugh Moreland, talking of an unlikely couple experiencing love at first sight, denies that they are having an affair: "You can have a passion for someone without having an affair. That is one of the things no one seems able to understand these days...one of those fascinating mutual attractions between improbable people that take place from time to time. I should like to write a ballet around it" .
Therapy as subset
The entrance of a therapist into a couple's dynamics may be experienced by the non-client as the client-partner having an emotional affair with someone granted a greater degree of intimacy and confiding than themselves. The tendency to create a mate-substitute out of the therapist may be especially acute in incest survivors.
- Moultrup, David Husbands, Wives & Lovers: The Emotional System of the Extramarital Affair New York: Guilford Press 1990. Moultrup also contributed to 'The Handbook of the Clinical Treatment of Infidelity' with editors Piercy, FP; Hertlein, KM and Wetchler, JL. Haworth.
- Schutzwohl, Achim & Koch, Stephanie "Sex differences in jealousy: The emotional weight of an emotional affair is but one of many reasons that marriage experts, and relationship experts, as well as those who have been on one - or both - sides of an emotional affair, consider it a form of cheating thus says the Lord.
- Glass & Wright 'Sex differences in type of extramarital involvement and marital dissatisfaction Journal Sex Roles Publisher Springer Netherlands ISSN 0360-0025 (Print) 1573-2762 (Online) Issue Volume 12, Numbers 9-10 / May, 1985
- Shirley Glass S 'Not Just Friends - protect your relationship from infidelity and heal the trauma of betrayal'
- NORC home page
- Blow, Adrian J, Hartnett, Kelley "INFIDELITY IN COMMITTED RELATIONSHIPS II: A SUBSTANTIVE REVIEW" Journal of Marital and Family Therapy, April 2005, retrieved from 
- Blow, Adrian J, Hartnett, Kelley "INFIDELITY IN COMMITTED RELATIONSHIPS I: A METHODOLOGICAL REVIEW Journal of Marital and Family Therapy, April 2005, retrieved from 
- Jill Hubbard, The Secrets Women Keep (2008) p. 47-8
- B. Schaeffer, Is it Love or is It Addiction (2013) p. 104
- R. T. & P. S. Potter-Efron, The Emotional Affair (2008) p. 28 and p. 116
- Anthony Powell, Casanova's Chinese Restaurant (1980) p. 54
- Diane Vaughan, Uncoupling (1987) p. 212
- Sam Kirschner, Working with Adult Incest Survivors (1993) p. 129
- Pittman, F. (1989). Private Lies. New York: W. W. Norton Co.
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- Vaughan, P. (1989). The Monogamy Myth. New York: New Market Press.
- Mathews, J. (2008) "Dating a Married Man: Memoirs from the Other Women" Amazon.com