dlovato030713.jpg What a surprise!

Demi Lovato recently made an unexpected admission during a WBLI radio interview when she revealed she has an older half-sister she never knew existed until this year!

"I have an older sister I've never known my whole life, who's in her 30's. She's my half-sister, but I talked to her for the very first time in my life around when I turned 20," she confessed.

The "Heart Attack" singer didn't offer any other details like the sister's name or whether she's her father's or mother's child, but she did explain how their first meeting went down.

"I asked her, I said, '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," she divulged.

The X-Factor judge was taken aback with her sister's sincerity, too!

"I thought that was so incredible. So, I actually have three sisters," she added.

Lindsay Lohan should take a page from Miss Lovato's book!