Adding to speculation that Caribbean singer Rihanna is re-uniting with ex-boyfriend Chris Brown was the fact that the ex-couple recently performed for a couple of songs together.

One was a remix of Rihanna's "Birthday Cake" and the other a newer version of Chris Brown's "Turn up the Music".

Earlier, in 2009, a case of Brown assaulting Rihanna led to their break-up. The two were, however, spotted together recently at Rihanna's birthday party.

Moreover, the two have been tweeting as well.

Brown tweeted: "Happy Birthday" to Rihanna, while the singer tweeted back: "Thanks".

Chris Brown is currently dating Karrueche Tran and we have no idea what is happening between Brown and Rihanna. But we would like to know more!