According to US Weekly, Perry isn't keen on the reconciliation with Brown and made a special request to be seated away from the couple at the Grammy Awards in Los Angeles on Sunday night (February 10).
A source said: "They aren't tight anymore because Katy doesn't approve of Rihanna dating Chris Brown."
A friend of Rihanna told HollywoodLife.com: "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."
Perry - who sat separately with her boyfriend John Mayer - was previously said to be barely speaking to Rihanna because she thinks she is 'making a huge mistake' by getting back together with Chris.
2013 Grammy Awards - Ceremony highlights in pictures:
Copyright: PA Images John Shearer / Invision / AP