Chynna and Bijou Phillips have known the truth for years now -- that their father and half-sister were longtime lovers -- but it's the way Mackenzie revealed their darkest "family secret" to the world that has them both upset. On Friday's 'Oprah,' Chynna revealed she was told the truth 12 years ago, and is proud of her half-sister for facing her demons. But she isn't without her reservations about the way Mackenzie Phillips rolled out the news, via a tell-all book titled 'High on Arrival.'

"Am I exceedingly joyful that my family secret that I told maybe my therapist, my husband and my very best friend in the whole word [is now public]? No."