R&B star Ray J is stunned by former lover Kim Kardashian's negative reaction to their leaked sex tape - insisting she should be grateful it launched her career.

The socialite and her sister Kourtney landed a reality show, Keeping Up With The Kardashians, off the back of her raunchy film with Ray J - but she is still angry with the 26-year-old, and he can't understand why.

He says, "I don't know how it got leaked. But It was great for her career. Will someone explain that to her?"

-Bootylicious Kim Kardashian Pictures

(This news article provided by World Entertainment News Network)