So who are these women whose marriage has benefited from swinging?
A Seattle stay-at-home mother of two, Kayla, 38, has been with her husband for 16 years and considers herself a happily married swinger.
D., professor of psychology at Barton College in Wilson, North Carolina, who has extensively studied swingers.
Gregory (names have been changed to protect privacy), a 40-year-old police officer with a strong build and an auburn goatee, leans into his wife, Jenna, a 28-year-old paramedic with long brown hair and sparkly hazel eyes, and whispers, "What do you think of them? "But since we launched 11 years ago, people have opened more than 7 million profiles." In the past seven years, SDC has also helped establish four swinger resorts.It's a warm, peaceful evening in a suburban Dallas neighborhood.Outside a colonial home with a well-manicured lawn, several cars are parked in the driveway. For most couples, "date night" means indulging at a new restaurant or going to the movies, but for Gregory and Jenna, who are newlyweds, it means having sex with other people. Although the term may conjure images of 1970s key parties, owners of swinger websites and event organizers say the popularity of the practice is increasing, with estimates ranging from 2 million to 15 million people engaging in the lifestyle worldwide."I've fooled around with women before, and it felt like a safe environment to do it again," she confesses.Now the couple swings about twice a month, and although many of their friends (including Jenna's maid of honor) are fellow swingers, she and Gregory say their conservative Christian families have no clue.