Katy Perry and Rihanna are good friends for quite some time now and there is good news for their fans. Perry has dropped hint that their new collaboration is a reality. Both multi-talented singers are working on a song and want it to be the best song their fans have ever come across.

"We've actually been talking about it for years, so we can't let anyone down," revealed the 29-year-old singer Perry over the weekend as she guest hosted the American Top 40 this weekend on Los Angeles radio station 102.7 KIIS FM.

"We have to do the best song ever. Beyond that, I think we'll definitely get around to it and when it happens, you are going to know," added the "Roar" singer.

Perry and the Barbados beauty Rihanna are both very fashion conscious and have shared the pictures of their Christmas nail art work on social media sites. While Perry posted a cute red and white picture of her perfect festive feet, RiRi went all colorful with hues of green, blue and red with an added sparkle on her hands.

"It's the little things," Perry captioned the picture which she posted over the weekend where her beautiful feet nails are covered in red and white nail paint with art work of Christmas tree and Santa Claus. The 29-year-old did not post the pictures of her hands but we are sure she must have managed to get the spirit right with the Santa-inspired manicure.

Rihanna on the other hand is wild and whacky and loves colour. Her long nails were done in maroon and green nail paint with added sparkle. "Christmas nail swag! #SantaHat #Mistletoe #SnowMan #CandyCane," the "Monster" singer captioned the picture, which can be seen here. Rihanna's recent hand tattoo and her several rings are visible in the picture too.

Both Riri and Perry are thick friends and love to do their nails in festive spirit. If their timings and likings are so much similar when it comes to fashion we couldn't help but wonder what kind of "best song" will they come out with if they work together. Let's wait and watch.