They had one of the best friendships in show business. Selena Gomez and Demi Lovato have been BFFs since they starred on Barney and Friends together, but like many friendships, it’s had its ups and downs that were known to the public eye.

So much happened behind the scenes in their friendship, but it seems like things have fizzled out between the two of them. “Selena has always tried to be nice to Demi, but over the last couple of years especially, the both of them have been through personal struggles,” a source told UsWeekly. “In the past, Demi felt like Selena wasn’t always there for her and that the friendship wasn’t reciprocated.”

What happened between Demi Lovato & Selena Gomez?

The big mystery is what actually caused the split in their friendship. Here’s a deep dive into their relationship of over 20 years.

2002: Selena and Demi star in Barney & Friends together

PH๏τo : Hit Entertainment. Courtesy: Everett Collection

Selena and Demi became friends on the set of the show Barney and Friends when they were 10 years old.

“I particularly remember Selena and Demi because they were really cute and very motivated,” Director Fred Holmes told International Business Times. “And the challenge with kids that age, especially boys, is finding kids that can stand up to the rigors of television. It’s a tough thing to do. They had to have a level of maturity that most kids that age didn’t have. And they were both great.”