R&B star Rihanna finally revealed at the World Music Awards that she is dating actor Josh Hartnett.

Although the couple had been very careful in keeping the relationship quiet, a photo emerged of the couple swapping spit at a New York night club last month.

And now the 19-year-old singer has confirmed the relationship.

"I've fallen for him big time. I would be lying if I (said) we were not more than just friends," she said.

"He is so hot and he is really sweet to me. When we hang out it feels right - even though it's still pretty new."

Rihanna has proved she really is a good girl gone bad, after photographs showing the R+B singer in an intimate embrace with a female friend surfaced online.

The Umbrella hitmaker, 19, was snapped fondling her pal's breasts on a recent night out while her friend poses provocatively for the camera. The photo - posted on MediaTakeOut.com - will come as a shock to her young fans, for the Bajan beauty is known for her clean-cut image.