THE SECRET LIVES OF WIVES

In 1643 Mary Latham, who was 18 years old and married, was hanged in Massachusetts with her lover James Britton. Since then, adultery has been a crime in many states. A woman accused of adultery could, in divorce court, lose her home, her income and her children. All that changed in the 1970s, when most states adopted "no fault" and "equitable distribution" divorce laws, in which nearly all the assets accrued to either partner during the marriage belong to the marriage and, in a divorce settlement, are split evenly. And unless a woman (or man) has been flagrantly or inappropriately sexual in front of the children, or has, in the frenzy of an affair, neglected them, infidelity does not legally affect settlements or custody. In researching her book "The Price of Motherhood," journalist Ann Crittenden found, however, that an implicit bias against female adultery still prevails in the country's predominantly male courtrooms--and that when it came to settlements, that bias was costly to women. "There may be no fault as grounds, but fault has not left the system," she says.

Unearthing infidelity is shattering to any spouse. Men can be as traumatized as women by such a revelation; they can also be more surprised. David, 39, a government worker in Washington, D.C., discovered his wife was cheating the day she told him she wanted a divorce. "Never in a million years did I think it was possible." He found out later that his wife had started seeing someone at work, someone David knew fairly well because the two couples often met socially. Once the reality set in, he couldn't get images of his wife and the other man out of his head. Beset by nightmares, he started taking antidepressants. "I felt shame for what had happened, like I couldn't keep a person happy enough to stay with me." Now, eight months later, David is beginning to date again. His divorce should be final this month.

Just over half of all cases of female infidelity end in divorce, says Susan Shapiro Barash, a professor of gender studies at Marymount Manhattan College and author of "A Passion for More: Wives Reveal the Affairs That Make or Break Their Marriages." But that number may be shrinking. The conservative-marriage movement, as well as recent books like Judith Wallerstein's "The Unexpected Legacy of Divorce," have created a backlash against separation and raised consciousness about the seriousness of its effects on children. Therapists who see the overworked professional set say they've noticed an interesting trend: people who have children and marry late in life tend to be less interested in cheating than their contemporaries who married earlier--and more willing to work it out when a woman (or man) does stray. These women have spent a lot of time alone, and they're wise to the benefits of companionship. They've also waited a long time to have families and have a realistic sense of what's at stake. "I think people try to stay together," says Alvin Mesnikoff, a psychiatrist with a private practice in New York. In spite of the temptations, "women want a relationship, and they're willing to work hard at it."

Divorce or no, how do responsible parents protect the hearts of their children when they're in the midst of heartbreak themselves? Therapists say kids don't care whether it's Mom or Dad who fools around--all they care about is knowing they're safe and that their lives will remain stable. It's difficult, but parents who are dealing with a revelation of infidelity need to protect young kids from the facts of the case, as well as from their own anger. "There are very few things I will be absolute about, and this is one of them," says Katz. "Everything [children] ask for is not something they want. And if they ask, you should say, 'Yes, you're right. Things are tense around here, but this is between Mom and me'."

Explaining infidelity to older children is somewhat more complicated. If a 15-year-old turns to his mom and asks, "How long has this been going on?" a truthful answer may be in order, says Berger, the Elkins Park psychiatrist. And if he asks, "How could this happen?" "It may be reasonable for Mom to say, 'You don't understand, dear, that Dad has been cheating on me'," Berger says. Sometimes correcting the record is all right. "There's nothing gained by one parent being a martyr to the other parent's mistreatment." What parents need to avoid at all costs is to wrap the children into the drama by treating them as confidants.

Nadine grew up in a small, Midwestern town, and when she was 13 years old, her mother cheated on her father, moved to a town two hours away and married the other man. "There weren't any fights, nothing crazy," says Nadine, who at 28 lives in a big city and works in finance. "We sat down at Christmas. We discussed that Mother was leaving; it was nothing we had done." She and her siblings continued to live with her father; her mother went to school conferences and games as she had always done. Her parents remained, as she puts it, "best friends." But Nadine's teenage years were difficult. She never warmed up to the new man. She felt abandoned.