Good people in good marriages are having affairs. More times than I can count, I have sat in my office and felt torn apart by the grief, rage, and remorse of the people I counsel as they try to cope with the repercussions of their infidelity or their partner's betrayal. In two-thirds of the couples I've treated in my clinical practice over the past twenty years, either the husband, the wife, or both were unfaithful. Broken promises and shattered expectations have become part of our cultural landscape, and more people who need help in dealing with them appear in my office every day. Surprisingly, the infidelity that I'm seeing these days is of a new sort. It's not between people who are intentionally seeking thrills, as is commonly believed. The new infidelity is between people who unwittingly form deep, passionate connections before realizing that they've crossed the line from platonic friendship into romantic love. Eighty-two percent of the 210 unfaithful partners I've treated have had an affair with someone who was, at first, "just a friend." Well-intentioned people who had not planned to stray are betraying not only their partners but also their own beliefs and moral values, provoking inner crises as well as marital ones. This is the essence of the new crisis of infidelity: Friendships, work relationships, and Internet liaisons have become the latest threat to marriages. As these opportunities for intimate relationships increase, the boundary between platonic and romantic feelings blurs and becomes easier to cross. Today's workplace has become the new danger zone of romantic attraction and opportunity. More women are having affairs than ever before. Today's woman is more sexually experienced and more likely to be working in what used to be male-dominated occupations. Many of their affairs begin at work. From 1982 to 1990, 38 percent of unfaithful wives in my clinical practice were involved with someone from work. From 1991 to 2000, the number of women's work affairs increased to 50 percent. Men also are having most of their affairs with people from their workplace. Among the 350 couples I have treated, approximately 62 percent of unfaithful men met their affair partners at work. The significant news about these new affairs -- and what is different from the affairs of previous generations -- is that they originate as peer relationships. People who truly are initially just friends or just friendly colleagues slowly move onto the slippery slope of infidelity. In the new infidelity, secret emotional intimacy is the first warning sign of impending betrayal. Yet, most people don't recognize it as such or see what they've gotten themselves into until they've become physically intimate. Most people mistakenly think it is possible to prevent affairs by being loving and dedicated to one's partner. I call this the Prevention Myth, because there is no evidence to support it. My experience as a marital therapist and infidelity researcher has shown me that simply being a loving partner does not ensure your marriage against affairs. You also have to exercise awareness of the appropriate boundaries at work and in your friendships. This book will help you learn to observe boundaries or set them up where you need to. It will tell you the warning signals and red flags you need to pay attention to in your own friendships and in your partner's. Most people also mistakenly think that infidelity isn't really infidelity unless there's sexual contact. Whereas women tend to regard any sexual intimacy as infidelity, men are more likely to deny infidelity unless sexual intercourse has occurred. In the new infidelity, however, affairs do not have to be sexual. Some, such as Internet affairs, are primarily emotional. The most devastating extramarital involvements engage heart, mind, and body. And this is the kind of affair that is becoming more common. Today's affairs are more frequent and more serious than they used to be because more men are getting emotionally involved and more women are getting sexually involved. Consider this surprising statistic: At least one or both parties in 50 percent of all couples, married and living together, straight and gay, will break their vows of sexual or emotional exclusivity during the lifetime of the relationship. It has been difficult for researchers to arrive at this absolute figure because of the many variations in how research has been conducted, in sample characteristics, and in how extramarital involvements have been defined. After reviewing twenty-five studies, however, I concluded that 25 percent of wives and 44 percent of husbands have had extramarital intercourse. This is startling news indeed. Vast numbers of Americans are preoccupied by an actual or potential betrayal of an intimate relationship. Their anxiety is not confined to a particular class, occupation, or age. Infidelity can occur in any household, not just in situations where partners are promiscuous or rich and powerful. No marriage is immune.