Jessica Simpson and her ex Billy Corgan are mixing business with pleasure -- Billy's recording the theme song for Jessica's new reality show, The Price of Beauty. "Billy plays guitar, and Jessica's written and performed the lyrics," a VH1 insider confirms to Life & Style exclusively. "It's cute that they came up with the idea together."

On Jan. 11, Jess, 29, and the Smashing Pumpkins front man, 42, went into an LA recording studio, where Billy was working on the Pumpkins' new project. "I am blessed," Jessica tweeted after the jam session. Viewers can listen for themselves when the series, which examines perceptions of attractiveness across cultures, premieres on March 15 at 10 p.m. on VH1.

For more, pick up the latest issue of Life & Style, on newsstands now!

Photo Credit: Retna