Nicole Kidman and Keith Urban have always been careful to keep their emotions firmly in check – at least in public. But last week, reunited at Sydney airport, the couple threw caution to the wind, racing to embrace as soon as Nicole and their daughters Sunday, 4, and Faith, 2, left the terminal.

And our sources explain there’s a very exciting reason behind the latest scene in their real-life love story. Members of the Urban clan’s inner circle have confirmed to Woman’s Day that Nicole and Keith are trying for another baby. “Even though Faith was carried by a surrogate, they’ve never stopped trying for another baby by natural means,” a source close to the family tells Woman’s Day exclusively.

“Nic is 45, so she knows it’s unlikely, but she and Keith do have a very passionate relationship so, as she says, ‘There’s always a chance.’ And it’s an open secret among their friends that Keith would love to have a son.”Keith, 45, has spoken positively about their surrogacy experience.

“Nic couldn’t get pregnant [with Faith], so we found a beautiful woman to help us,” he says. Now friends are speculating that the couple are deciding to go down that path again. “Nic knows there isn’t a strong chance she will conceive again on her own,” a close friend confides. “But just in case, she isn’t taking birth control. She and Keith have considered the same surrogate who gave them Faith to help them have baby number three.”

Read more about Nicole and Keith's happy news in this week's Woman’s Day on sale Monday February 4, 2013.