Rihanna reportedly spent Valentine's Day with ex-boyfriend Chris Brown.

The pair's relationship hit headlines about three years ago, after an argument before the 2009 Grammys turned violent. Chris was arrested and charged with felony battery on his then-girlfriend, and given a restraining order.

Rihanna and Chris seem to have struck up a friendship again following the messy break-up, with the pair taking to their Twitter pages to converse. They have also been spotted partying at the same clubs.

Now reports claim the pair spent Valentine's Day together this week with Chris attending Rihanna's pre-birthday party in a Beverly Hills mansion.

Rihanna who was joined by fellow songstress and newly-single Katy Perry was seen enjoying herself around her former beau.

"All I can say, CB was invited and she [Rihanna] was acting like the happiest girl on her birthday and probably got what she asked for," a source told British newspaper The Mirror.

Rihanna was seen having fun at the party, with Bruno Mars and Kelly Rowland among the guests. The Bajan beauty reportedly stayed largely in the limelight, with Chris choosing to keep a low-profile.

"Rihanna and Katy had everyone going crazy. By the end of the night they started a cake fight and were dancing together while Bruno and Chris looked on open-mouthed, cheering," the insider added."RiRi made sure Chris was having a good time but then he kept a low profile, spending most of the night in a corner with a few pals.

"At one point Katy danced so much she broke her heels and had to leave the party barefoot. Rihanna also had her own wardrobe casualty when her corset came undone but she didn't let that stop the fun."