RICHIE SHOWS OFF SLIM POST-BABY BODY

Two weeks after welcoming daughter Harlow, Nicole Richie is skinny again.

Clad in a black hip-hugging dress, Richie, 26, and her rocker beau Joel Madden joined new grandfather Lionel Richie at a birthday bash Friday for Richie's manager Benny Medina in Los Angeles (Medina recently brokered Richie's million-dollar sale of her baby pictures).