Before they took the world by storm as pop princesses of the first order, Demi Lovato and Selena Gomez were just two kiddos beating the heat in water wingies. Oh, and singing songs with Barney the Freakin' Dinosaur.

It’s no secret Dems and BFF Selena broke into Hollywood courtesy of the best imaginary friend in town. They warmed up their windpipes with such classics as the zippy tune featured below, which we've highlighted in honor of Demi's 21st birthday today, August 20! Be warned, though: the lyrics “If I lived under the sea sea sea, I think it would be as neat as it can be be be” will be stuck in your head all day post-viewing.

But as cute and innocent as Demi looks splashing around in the kiddie pool, it turns out the songstress had other things on her mind — namely who was hiding under that suit.

“I would imagine him to be very attractive,” she told The Guardian. “Because he’d have to be a muscular guy to carry that suit. And he’d happen to also have a really good-looking face. And he may or may not have been my crush when I was growing up on that show.”

So that’s how Demi likes 'em: tall, purple, and imaginary. Take note, Wilmer Valderrama (that is if you two have finally decided to get back together).

Turns out Barney wasn’t the last dinosaur Dems would star alongside but he was the nicest. When asked who is easier to work with — Barney or fellow X Factor judge Simon Cowell — Dems didn’t hesitate. “Definitely Barney.”

Are you surprised that Demi was on Barney? Sound off below, and leave your birthday wishes for her, too!

Sources: Perez HiltonThe Guardian