LOS ANGELES, CA - FEBRUARY 14: Singer Demi Lovato attends Topshop Topman LA Grand Opening at The Grove on February 14, 2013 i
Jason Merritt

During an otherwise run-of-the-mill interview with a Long Island radio station, Demi Lovato beat TMZ to the punch and let loose with a major bomb about her personal life: She has a secret half-sister.

"I just learned I have an older sister who I never knew," Lovato casually told WBLI radio. "She's in her thirties. She's my half-sister but I talked to her for the very first time in my life when I turned 20." FYI, Lovato turned 20 last August.

The X Factor judge and her older blood relative hadn't interacted before then because Lovato had no idea she existed. "I asked her, 'Why haven't you ever contacted me?' She said, 'Well, I never wanted you to think I wanted anything from you. So I've just been kind of waiting to see if you wanted a relationship.' I thought that was so incredible." 

Always keen to maintain some level of privacy, the "Heart Attack" singer didn't reveal whether this half-sister comes from her mother or father. Regardless, we can now say Demi Lovato has a demi-sister.