On a quiet street in a Dallas suburb, dozens of guests have been meeting for sex in a private house. Do they have a right to party?

The Pit': Multiple beds form a platform for group activities, in this photo taken from the Cherry Pit's Web site

Jim Trulock and Julie Norris look like an average suburban Dallas couple. He's a graying middle-aged divorcé pushing 60. She's 30 years younger but partial to frumpy floral dresses. But on weekends their late-'70s split-level house in the southwestern Dallas suburb of Duncanville is transformed into "The Cherry Pit."

Jim and Julie are swingers—couples who socialize sexually with other couples or singles living "the lifestyle," as they call it. Surprisingly, the Cherry Pit parties held in the Texan notch of the Bible Belt went relatively unnoticed for years, despite attendance of sometimes 100 or more invited guests.