Chris Brown is ''having fun'' with Rihanna.

The 'Fine China' singer - who has an on/off relationship with model Karrueche Tran - insists his relationship with his former girlfriend, who he was convicted of assaulting in 2009, is nothing ''serious'' and they're just enjoying each other's company at the moment.

He said: ''We're friends. Nothing too serious... We're not trying to start a life together right now, we're just having fun.''

It was believed 'Drunk Texting', a track on the 25-year-old star's new album 'X', is about Rihanna, and while Chris insists it isn't, he doesn't mind theories being shared because he thinks it encourages record sales.

Asked if the track is about Rihanna, he said in an interview on US TV show 'Entertainment Tonight': ''Oh no, not at all. I think that's just the fans' perception or the media's perception at all times because of our history. But whenever we do music, people can make the assumption and that's fine because if they buy more because they think that, then go ahead and buy a thousand copies.

''But as far as me writing and going into that, I don't really try to put my focus on Rihanna every song. At the end of the day it's almost six, seven years later. It's like, how many more times am I going to talk about the same situation?''