Apparently she had no problem having the bants with Calvin Harris, though. It's just Rita she repeatedly snubbed by all accounts. We reckon we know why.

Look at what Rihanna was wearing to Jay-Z's pre-Grammy party... She possibly didn't want to be photographed with Ora who looked only beauriful on the night itself. Not like she robbed a shirt and an apron off the back of a butcher.

OK, so what she chose to wear to Jay-Z's party is a bit 'Pocahontas off to play mixed doubles at a strippers convention', but it's still preferable to Rihanna's ensemble.

This is what reportedly happened on the night. Rihanna refused to speak to Rita at the Grammy Awards parties over the weekend. She happily chatted to Rita's on/offer Calvin Harris at several pre and post-ceremony bashes - including a brunch thrown by Jay Z's Roc Nation, which manages both their careers - but 'deliberately' snubbed Rita because she "isn't a fan" of her. That's strange because they're soooooooooooooo alike.

A source told The Sun: "Rita and Rihanna were at the same parties all weekend. Rihanna deliberately kept her distance. She talked with Calvin at length but didn't acknowledge Rita. It was awkward because they have the same management team and move in exactly the same circles. Rihanna's never been much of a fan of Rita because her style is so similar and they compete over songs."

Rihanna didn't attend the Grammy Awards at Los Angeles' Staples Center on Sunday despite winning Best Urban Contemporary Album for Unapologetic but later admitted she was thrilled to win the prize. She tweeted: "$weet $urprise, pretty ph*cking rad! Thank you.(sic)"

Instead of attending the awards, Rihanna was spotted at The Young Money Cash Money Records party at Greystone Manor with rumoured boyfriend Drake instead. During that bash she would have been busy avoiding yet another rival - Karrueche Tran was also in attendance.