Mackenzie Phillips: I Slept With My Dad

Mackenzie Phillips had a 10-year sexual affair with her father, the Mamas and the Papas founder John Phillips, she reportedly alleged in her new book, “High On Arrival.”

“I woke up that night from a blackout to find myself having sex with my own father,” she wrote regarding the night before her 1979 wedding to Jeff Sessler, according to multiple sources.

As previously reported on AccessHollywood.com, the “One Day At A Time” actress also told Oprah Winfrey in an episode of “The Oprah Winfrey Show” to air Wednesday that John had shot her up with heroin the first time she used the drug.

Her half-sister, Chynna Phillips, told Us Weekly on Wednesday that she’d heard of the incestuous relationship in 1997, before boarding a flight at LaGuardia Airport in New York City.

“She said, ‘I don’t know why, but I just really felt the need to call you and tell you something that I think you need to know,’” Chynna told the mag. “And she went on to tell me that she had had an incestuous relationship with our dad for about 10 years.”

Chynna also confirmed that Mackenzie had told her the story of how the alleged affair began.

“After long nights of heroin use, she’s claiming that she once woke up and that my father was on top of her having sex with her,” Chynna said. “Was he actually raping her? I don’t know. Do I believe that they had an incestuous relationship and that it went on for 10 years? Yes.”

Both Mackenzie and Chynna had scheduled separate appearances on ABC’s “The View” which have since been canceled, Access learned on Wednesday. 

Mackenzie and Jeff Sessler split in 1981. In 1987, during the period she alleged she had a relationship with her father, she and husband-to-be Michael Barakan had a son, Shane.

The troubled star was arrested in August 2008 at Los Angeles International Airport. She was found carrying, “what appeared to be heroin and cocaine in baggies and balloons” airport police told Access at the time. In October of that year, she pleaded guilty to cocaine possession and later thanked authorities for “probably saving my life.”