Ian Zierling, Ivana Trump Set for OPRAH: WHERE ARE THEY NOW? on OWN, 12/22

Ian Ziering talks Sharknado and stripping, Ivana Trump fesses up about her penchant for dating younger men, Christian Siriano shows off his fab NY apartment, and Debby ("You Light Up My Life") Boone confesses her love for Sin City on an all-new episode of "Oprah: Where Are They Now?" airing this Sunday, December 22 at 10 p.m. ET/PT on OWN: Oprah Winfrey Network.

Featured on the show:

He'll always be Steve Sanders to Beverly Hills, 90210 fans, but today Ian Ziering opens his home and introduces his wife and two daughters, shares how he got in shape to Take It All off for Chippendale's, and how he almost passed up the role in the Syfy social media phenomenon Sharknado.

Ivana, the original Mrs. Trump, opens up about Life After The Donald, being a grandmother, and dating younger men.

Project Runway winner Christian Siriano provides a tour of his gorgeous NY apartment and talks about his tremendous success, and perennial "good girl" Debby Boone reveals how Sin City, USA (Las Vegas) inspired her singing career, and shows the secret room in her house that she has never shared before.

Also ... updates with Steven "Cojo" Cojocaro, Cakelove bakery founder Warren Brown, and Khadijah Williams, the girl who went from skid row to Harvard University.