All societies regulate sexual behavior and use marriage as a means to control the be­havior of their members to some degree. Our society is one of the few that have tradi­tionally forbidden sexual contact outside of marriage; research estimates that less than 5% of all societies are as strict about forbidding extramarital intercourse as ours has been (Leslie & Korman, 1989). Our opposition to sex outside of marriage stems from our Judeo-Christian background, and although today it is not as shocking as it used to be, there is still a strong feeling among Americans that extramarital sex is wrong.

Almost all couples, whether dating, living together, or married, expect sexual ex­clusivity from each other. Although extramarital sex refers to sex outside of marriage, we are also referring here to extra-relationship sex, or dating couples who have sex with someone other than their partner. Not surprisingly, adults in the United States are more likely to cheat while living together than while married (Treas & Giesen, 2000). Those who cheat in intimate relationships have been found to have stronger sexual interests, more permissive sexual values, less satisfaction in their intimate relationship, and more opportunities for sex outside the relationship (Treas & Giesen, 2000).

Half the states in the United States have laws against sex outside of marriage, al­though these laws are rarely enforced. If they were enforced, a cheating spouse would be unable to vote, practice law, adopt children, or even raise his or her own children. Even though many of these laws aren’t enforced, attitudes about extramarital sex in the United States remain fairly negative. Over the last few years, attitudes about extramar­ital sex have become even more negative (Thornton & Young-DeMarco, 2001).

Laumann and colleagues (1994) found that 20% of women and 15% to 35% of men of all ages reported that they had engaged in extramarital sex while they were married. Even for those couples who never consider sex outside of marriage, the possibility looms, and people wonder about it—what it would be like, or if their partners are indulging in it.

How does an extramarital affair begin? In the first stage, a person might become emotionally close to someone at school, work, a party, or even on the Internet. As they get to know each other, there is chemistry and a powerful attraction. This moves into

the second stage, in which the couple decides to keep the relationship secret. They don’t tell their closest friends about their attraction. This secret, in turn, adds fuel to the pas­sion. In the third stage, the couple starts doing things together, even though they would not refer to it as “dating.” Each still believes that the relationship is all about friendship. Finally, in the fourth stage, the relationship becomes sexual, leading to an intense emo­tional and sexual affair (Layton-Tholl, 1998).

Extra-relationship affairs can have a similar effect on a dating relationship. Overall, married couples are the most deceptive about sexual affairs outside of their relationship. Both nonmarried heterosexual couples and lesbians who live together have been found to be less deceptive and secretive than married couples.

There appear to be some gender and racial differences in acceptance of extramarital affairs. Males tend to be more accepting of extramarital sex than females (Wilson & Medora, 1990). Overall, women have been found to experience more emotional distress about infidelity than men do, although a woman is more likely to be upset about emo­tional infidelity, whereas a man is more likely to be upset about his partner’s sexual infi­delity (see Chapter 7 for more information about gender differences in jealousy; Nannini & Meyers, 2000). Interestingly, men and women often accept more responsibility for their partner’s infidelity when it was emotional in nature. Perhaps this is because they feel their own emotional unavailability led their partner to seek emotional comfort somewhere else (Nannini & Meyers, 2000). Overall, women have been found to have more emotional, rather than physical, affairs.

Although many people think that sexual desire drives an extramarital affair, research has found that over 90% of extramarital affairs occur because of unmet emotional needs within the marital relationship (Layton-Tholl, 1998). Those who cheat may be looking for the original spark and passion from earlier in their marriage. In fact, when asked, the majority of people claim that marital dissatisfaction is a justifiable reason for engaging in an extramarital affair (Taylor, 1986). Laumann and colleagues (1994) found that, overall, couples are faithful to each other as long as the marriage is intact and satisfying.

Most people who engage in extramarital affairs feel intense guilt about their behav­ior. Some do go on to marry their new partner, but these relationships are often fraught with turmoil because the relationship was based on a lie from the beginning. A. P. Thompson (1984) claims that there are three types of extramarital affairs: sexual but not emotional; sexual and emotional; and emotional but not sexual. Twenty-one percent of respondents having extramarital sex were involved in predominantly sexual affairs; 19% in both sexual and emotional affairs; and 18% in affairs that were emotional but not sex­ual (the remaining affairs did not fit clearly into any of these categories). Affairs that are both emotional and sexual appear to affect the marital relationship the most, whereas affairs that are primarily sexual affect it the least.

Gender differences play a role in the type of extramarital sexual relationships that oc­cur. Women are more likely than men to have emotional but not sexual affairs, and twice as many men have sexual affairs. Research has also found that the more positive a woman’s attitude is toward sexuality, the longer she will stay in a primarily sexual extramarital af­fair. However, attitudes about sex are often unrelated to the length of the emotional type of extramarital affair. Age differences have also been found—men are more likely to have extramarital affairs when they are younger, whereas women are more likely to do so when they are older. In addition, women who have extramarital affairs are less sex typed and are more independent and assertive than women who do not (Hurlbert, 1992).

Can a marital relationship continue after an extramarital affair? Yes, but it can be difficult. Often the male partner who has an extramarital affair adds further distress to his wife by mislabeling her reactions and emotions (Gass & Nichols, 1988). For exam­ple, he may try to distort reality so that his wife thinks she is imagining things. All in all, regaining trust and reestablishing a relationship will often take time after an affair.