Threesomes: A User's Guide

"There's no such thing as too much decision making beforehand," says Jen Sincero, author of The Straight Girl’s Guide to Sleeping with Chicks. "You also need to make sure that both partners feel comfortable pulling the plug in the middle if things start feeling weird."

Which is exactly what happened to Jim* and Tracy*. After she agreed to—and enjoyed—a threesome with another woman, she requested they try it with another man. Believing the situation to be a sort of quid pro quo, Jim agreed despite his misgivings.

"I'm not a homophobe and I'd enjoyed seeing my wife with a woman, so I felt an obligation to say yes to a man," admits the 34-year-old lawyer. But before anyone's trousers dropped, he changed his mind. "Thankfully we had a 'safe' word I could say to stop everything," Jim recalls ruefully. "I had really been hating every second of it, and I knew it’d get to the point where our whole marriage could suffer."When Lesbian Obsessions Backfire On Men

"We didn't really 'choose' the three friends we've been with—it was all more a function of circumstance," explains Jaime, a 29-year-old speech therapist who has been with her boyfriend for six years. "It always started after a party, and it always ended with hugs; it was really nice. But my boyfriend and I had discussed the theoretical possibility of a threesome beforehand. And we knew the people well enough to believe they'd be OK with things afterwards, but not so well that a need to sever ties would have been hard."

So if you and your partner are truly ready to share your sex life with another person, there are potential collaborators everywhere—that is, if you make rules that will keep everyone happy and satisfied. That said, coworkers should probably stay a fantasy—no matter how hot the office manager is. Are Sex Parties The New Vibrator?

Whether you're interested in men or women or both, it's vital that everyone involved—including the easy-to-overlook third person—be comfortable with each other. When you’re ready to find a partner, you can go about it in any number of ways.

There are polyamory clubs all over the world; try googling "polyamory munch," which sounds filthy but is actually a nonsexual gathering in which groups of people meet to discuss their interests and find potential partners. However, while many people recommend that the third person be a virtual stranger, the right friend can be an ideal partner as well.