"Can already mated people have opposite-sex friendships?" asks David Schmitt, professor of psychology at Bradley University in Peoria, Ill., who helped conduct that research.
"I think they can." But the hard data he found suggest that as much as 15% of the time, such relationships end in a poach.
No wonder tongues cluck and fingers wag. Wary husbands and wives have an uneasy sense of the temptations out there, even if they trust their spouses. "It's like when your teenage daughter goes to a concert dressed like a slut," says Bleske-Rechek.
"She says, 'I'm not going to do anything.' And her father says, 'It's not you I'm worried about.' "
But the danger that lurks in a world, and a workplace, full of opposite sex people who have a lot in common doesn't mean they can never be friends once one of them has committed to another.
They just have to be careful, and use common sense. Estimates of extramarital affairs, one form of mate poaching, range from 20% to 50%, depending on the sample and methods of multiple studies. With temptation that common, says Helen Fisher, anthropologist at Rutgers University and author of "Why We Love," opposite-sex friends can expect a friendship, at some point, to cross the flirtation line. They need to be ready to deflect temptation. "Start out by putting a picture of your wife or husband on your desk," she says. "And talk about them a lot."
Women should make a point of meeting their male friend's wife, men of meeting the husband of a woman friend. "Meet the wife, and fawn on her," Fisher says of her own technique as a single woman. "Choose her side of the table to sit on. Make eye contact with her. If you can tell her you've got a boyfriend you love, that'll help." Make the spouse a friend too, with the goal of defusing jealousy, of making the spouse feel that the friendship is no threat.
To silence wagging tongues, opposite-sex "just friends" shouldn't touch, shouldn't share bites of food over lunch, shouldn't stand too close to each other. Crossing those lines fuels gossip. Worse, it can lead to the slippery slope of greater intimacy. But if people talk, and there's nothing to talk about, "you've got to just flat-out deny it," Fisher says.
Above all, says Stanley Charnofsky, therapist and psychology professor at Cal State Northridge, put your mate first. It's not just an affair that can feel like betrayal, he says.
"Is there such a thing as a nonsexual affair? What if you go for coffee at 10 o'clock every day with someone from work, and talk intimately with them," he says. "Then you go home, and you don't talk to your spouse." The platonic friend is getting some of the spouse's major perks, even if it isn't sex.
Keep your spouse informed, he says. Tell your partner about your friend and what you've talked about. Respect a spouse's feelings. "Opposite-sex friendships are possible. They're healthy," Charnofsky says. "But they definitely have to be lower than, lesser than, the one with your mate. They have to be secondary."
It's difficult, relationship researchers say, but opposite-sex friendships are worth the effort. "It would make the world a pretty boring place if you could associate with only half the population," Buss says.