"THE NEW SEX: STRANGE ARRANGEMENTS," ON "20/20," FRIDAY, APRIL 20

Wives with boyfriends and husbands with girlfriends� female celebrities breaking the taboo and talking about sex in ways they never have before� women paying cute guys to date them� open marriages� what's going on with sexual arrangements in America today? Anchored by Elizabeth Vargas and including the first primetime interview with 50 Shades of Grey author E.L. James, "20/20" goes inside this new world of strange arrangements. "The New Sex: Strange Arrangements" airs on "20/20" on FRIDAY, APRIL 20 (10:00-11:00 p.m., ET) on the ABC Television Network. Reports include:

50 Shades of Grey: E.L. James, the author of one of the most buzzed about books this year - dubbed "mommy porn" for its graphic sexual content and the frenzy it's generated among female fans - sits down with Elizabeth Vargas for an exclusive primetime interview. Her trilogy, 50 Shades of Grey, 50 Shades Darker and 50 Shades Freed, has taken the publishing industry and most recently Hollywood by surprise with its rapid rise from a fan fiction e-novel to New York Times bestseller. Calling it a "love story with kink," James shares how the steamy novels were created and how her life has changed.

Celebrity Sex: Gwyneth Paltrow, Sarah Silverman, Jane Fonda and many other high profile female celebrities are discussing sex in a graphic way you've never heard before. But why? Chris Connelly talks to Amanda de Cadenet, the host of a new provocative talk show, "The Conversation" (airing soon on Lifetime) about how she dares to ask about such taboo topics.

Open Marriage with Kids: With one in two marriages ending in divorce, some couples, instead of blowing up relationships, are quietly expanding them. "20/20" profiles two couples who are living the open marriage lifestyle while raising kids and growing old together, and they say it has made their relationships better. Having other paramours not only spices up their love life but the romantic intimacy builds a kind of extended family that actually helps with childrearing. Vargas reports.

Gigolos: As women acquire more money and power, some are not afraid to admit that they are paying for the man on their arm - men known as gigolos. And, as Juju Chang reports, the Showtime reality series "Gigolo" has made these exploits more visible.

Preview: http://abcnews.go.com/2020

David Sloan is executive producer of "20/20."