Now this is a horrifying revelation.
Mackenzie Phillips, the trouble-plagued eldest daughter of the late Mamas & the Papas frontman John Phillips, says in an interview with Oprah Winfrey, airing tomorrow, that she was a victim of rape at the hands of her famous father.
Phillips says in her new memoir, High on Arrival (which she discussed with the daytime queen), that she confronted John, who died in March 2001, about their sordid past, saying, "We have to talk about when you raped me."
To which John replied, according to his daughter, "You mean when we made love?"
"Interviewed One Day at a Time's Mackenzie Phillips," Winfrey wrote on Twitter this afternoon. "Thought I'd heard it all…beyond shocking! We're airing it Wednesday."
Phillips, 49, is John's daughter with his first wife, Susan Adams. Bijou and Chynna Phillips, who also have different moms, are her half-sisters.
The rock 'n' roll progeny has battled drug addiction and has been in trouble with the law off and on since she was a teenager, problems that derailed her promising acting career. Most recently, she was arrested for cocaine possession at Los Angeles International Airport last summer.
She also talks in her book about her father supplying her with drugs when she was a kid, an unsavory habit that ultimately led to the biggest parent-child betrayal of all.
"On the eve of my wedding, my father showed up, determined to stop it," Phillips wrote. "I had tons of pills, and Dad had tons of everything too. Eventually I passed out on Dad's bed.
"My father was not a man with boundaries. He was full of love, and he was sick with drugs. I woke up that night from a blackout to find myself having sex with my own father."
Phillips was 19 at the time.
"I was a fragment of a person, and my secret isolated me," she wrote.
Shake off the willies with a glance at the Big Picture gallery.