Demi Lovato has secret half-sister: Strangest celeb family drama?

We can say this much about Demi Lovato: She's certainly never boring.

Last year she made the rounds opening up about her eating disorder, self-harm and abuse of drugs and alcohol. Now the 20-year-old former Disney star reveals that she has an older half-sister she never knew existed until 2012.

SODAHEAD SLIDESHOW: See the strangest celebrity family dramas.

"She's in her thirties," Lovato told "Dana & Jeffrey in the Morning." She continued, "She's my half-sister and I talked to her for the very first time in my life around when I turned 20. I asked her, 'Why haven't you ever contacted me?' and she just said, 'Well, because I never wanted you to think I wanted anything from you. So I've just kind of been waiting to see if you wanted a relationship,' and I just thought that was so incredible."

Lovato is far from the only star with an unconventional family life. Beyonce fired her dad and ex-manager Mathew Knowles after an audit purportedly showed that he had stolen funds from her. (He denied the allegations). Angelina Jolie and her dad Jon Voight became estranged when Voight said his daughter had "serious mental problems," which she feared would jeopardize her adoption of her son Maddox.

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Shirley MacLaine's daughter Sachi Parker recently claimed in her memoir that she rarely saw her famous mother and missed her so much that she looked forward to seeing her on an airplane movie screen. And who could top the sad story of "One Day at a Time" actress Mackenzie Phillips, who claimed in her memoir to have had a years-long sexual relationship with her father, The Mamas & the Papas singer John Phillips?

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From Demi Lovato to Paris Jackson, let us know: Which celeb had the strangest family drama?