Rihanna releases X-rated Chris Brown duet

Rihanna marked her 24th birthday by releasing her hotly-anticipated duet with ex-boyfriend Chris Brown on Monday (20Feb12).

The Umbrella singer took to her Twitter.com page on her big day to share the ex-couple's sexually-charged collaboration Birthday Cake, a remix of an interlude featured on her latest album Talk That Talk.

The raunchy track proves the pair's notorious 2009 bust-up is firmly in the past.

The controversial stars didn't stop with one track - Rihanna returned the favour by recording vocals for a new version of Brown's Turn Up The Music, which he also posted online for fans.

The two songs have arrived three years after the stars split following Brown's arrest for assaulting Rihanna on the eve of the 2009 Grammy Awards.

The altercation landed Brown a conviction and saw him sentenced to probation and community service, while he was also ordered to stay away from the Umbrella hitmaker.