"You were both pregnant at the same time," she says, more a statement than a question. Both women nod and after a moment's pause, Kristina adds, "What about Angela?" Kristina is referring to her 16-year-old sister.

"Well..." her mom clears her throat. "It worked so well the first time, and we didn't want you to be an only child, so we did it again a couple of years later."

"Swapping partners, again?" Lauren asks.

"Yes," mom says.

"What about now, when the four of you go to the cabin?" Lauren asks and I bet mom wishes she had never promised that she would always tell us the truth no matter...