Katy Perry and Rihanna, who were once thick friends, are not speaking to each other. Katy is avoiding Rihanna because she has reunited with rapper Chris Brown.
Perry reportedly made a special request to be seated nowhere near the couple at the Grammy Awards Sunday.
"They aren't tight anymore because Katy doesn't approve of Rihanna dating Chris Brown," a source told usmagazine.com.
But friends close to Rihanna, 24, insist she has no problem with Perry, 28, but doesn't care what anyone thinks about her relationship.
"Rihanna doesn't have a problem with anyone and could give a f**k about what anybody thinks about her relationship. She was focused on her and Chris and enjoying her night," said another source.
Perry thinks Rihanna is making a huge mistake by getting back together with Brown.
The last time Perry and Rihanna were spotted hanging out together was at the MTV Video Music Awards in September and at the award function Rihanna shared a public peck on the lips with Brown for the first time since their 2009 break-up.