Nicole says she's ashamed to admit she's been smoking for years…but until recently, her parents didn't even know.
"I told them before [the show] so they wouldn't be totally shocked," she says. "My mother said, 'You don't smoke.' 'Yes, I do.' My sister talked to my mother, and my mother still didn't believe her. She said, 'Mom, Nicole is actually in Chicago. She's going to Oprah to quit smoking."