Rihanna has been partying with friends so much she feels like it should be her birthday.

The singer has been promoting her new movie Battleship all around the world recently, including spending time in Australia.

Although her work schedule has been hectic, Rihanna has still found time for fun.

She has posted a series of photos of her with friends on her Twitter page, including one where she is posing with a female pal. The pair seem to be on top of a high building and both have one leg raised in the air, showing off their toned legs in bikinis.

In a seemingly cheeky reference to the wild parties she is said to love, Rihanna captioned the shot: "It's not even my birthday."

In another shot, Rihanna is seen hugging another friend while wearing a black maxi-dress and a pair of over-sized shades.

"Aw man I love my b***hez (sic)," she wrote next to the image.

The 24-year-old star didn't only praise her friends on the social networking website. She also revealed a penchant for a rather more unsavoury pastime, when someone from an X-rated website messaged to say how much he admired her.

The site specialises in showing off Brazilian and other Latino men, which hasn't gone unnoticed by Rihanna.

"If u only knew how much @Rihanna looove u!!! #Brazilians #Latinos (sic)," she wrote.