Adam Levine has dated some of the hottest bachelorettes in Hollywood so his dating rules must work.

The very lucky singer, who has been seen with Jessica Simpson and Natalie Portman, told Seventeen magazine that he has advice that he sticks to when trying his luck with the fairer sex.

Jessica Simpson is "really happy" since splitting from John Mayer, her friends have claimed. Jessica celebrated her newly single status with a girls-only night in Los Angeles last week - and reportedly told pals she was "happy" about her recent break-up.

A source told Us Weekly magazine: "She was telling friends, 'We were so different, we were fighting so much. I'm really happy to be out of that relationship. This time, it's totally done.'"