• US POP stars Rihanna and Ciara: Ciara said on TV that Rihanna snubbed her at a party. Rihanna then took to Twitter and said: "My bad, Ci, did I forget to tip you? #howrudeofme."

Ciara hit back: "Trust me, Rihanna, you don't want to see me on or off the stage."

Rihanna told Ciara, who has been dropped by her record label: "Good luck with booking that stage you speak of."

• Comedian Nick Cannon and TV host Chelsea Handler: Handler joked on Twitter after hearing that Cannon was going on tour: "I just heard Nick is starting a comedy tour. Who's doing the comedy?"

Cannon responded: "Everyone knows @Chelseahandler had sex with the head of E! for her show. So when it's cancelled does he get residual p***y for the reruns?"