Katy Perry and Rihanna have been celeb besties forevs, but they seem to be experiencing a rift and its name is Chris Brown. Apparently, Katy is none too happy about the ChRihanna reunion and disapproves of the pair.

RiRi probably doesn't care, since she pretty much said that she has no concern over what anyone thinks about her reunion with Breezy in her Rolling Stone cover, where she confirmed the relationship. But KP is her BFF, who can always pull the "You didn't come to my wedding" card, since Ri skipped Perry's nuptials to Russell Brand in 2010 because she was wrapping her album. Yes, we know, they've since divorced.

But back to the topic at hand.

Gracia claims that the friendship is on fragile ground. "Katy was always the one person who could really stand up to Rihanna," a source said. But standing up to Ri isn't an option here. The source said, "When it comes to Chris, Rihanna isn't willing to listen. Katy is still incredibly angry about what Chris did, and she doesn't believe he can change."

Perhaps Perry is 'Wide Awake' when it comes to Breezy? Or maybe, just maybe, Ri is really evolved when it comes to the concept of forgiveness?

But Breezy and his bad behavior aren't the only thing that bothers the 'Wide Awake' singer. She doesn't like RiRi's party lifestyle, either, and is concerned about her health.

"She has stuck her neck out for Rihanna, and so it really hurt when Rihanna ignored her advice," the source said. "She said she couldn't stick around and watch someone she loves make such a big mistake, and that she had to walk away. They haven't spoken for months. Chris is like Rihanna's addiction and no one can talk any sense into her."

This story begs the question – does anyone other than RiRi like or support Breezy, besides Team Breezy, that is? Maybe they are so "good" together because it is them against the world.

Watch the Katy Perry 'Wide Awake' Video