Selena Gomez and Demi Lovato were thought to be the closest of friends, but it appears they are just beginning to enter their own feud. Signs that the two stars are not seeing eye-to-eye first surfaced when Lovato unfollowed the 21 year-old singer on Twitter, and even may have called her a b---h in a since deleted tweet.

Demi Lovato
Lovato unfollowed Gomez on Twitter

"Swimming away from the bulls--t bye b--ch," the cryptic tweet reportedly read, along with a photo of the 'Heart Attack' singer swimming in the sea. Although it isn't clear if the post was directed at Gomez, Lovato unfollowing her on-off BFF heavily suggests it was.

Even though the tweet was deleted from her account, it still remains circling the web.

The duo have known each other for many years since starring in on 'Barney & Friends' together, and back in February Lovato opened up about how "amazing" Gomez is.

"Selena is, I've known her for 14 years and we've been best friends," the former X Factor judge told E! News. "That's all of her business, and I just want to let her do her thing. And yeah, she's amazing. I love her."

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And only matter of weeks before these kind words, Lovato said herself and Gomez are "really, really close," when talking to On Air With Ryan Seacrest. "Any advice I had for her, we talked last night and-you know-it's between us. But I love her so much."

Adding, "We have an incredible friendship," Selena "is strong! She's doing really well right now!"

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The 'Come & Get It' singer also spoke candidly of their friendship, and previous falling out, in the March issue of Seventeen Magazine.

Selena Gomez
Lovato's problem with Gomez is still unclear

"I've known her since we were 7, and we did fall apart for a while," Gomez said. "She was going through things and I was so young and it was confusing.I processed it saying, 'OK, I don't understand what she's going through so I'm just going to do this.'"

"I don't think it was fair," she added. "I'm so happy that I have her back in my life now."

So it still remains a mystery why the pair have fallen out once again.