Sean Penn’s New Main Squeeze

He’s always been popular with the ladies, and Sean Penn has a new babe on his arm and her name is Shannon Costello.

The “Mystic River” actor met Costell back in 2009 and in 2010 she became the communications director of his J/P Haitian Relief Organization.

Additionally, Shannon worked on Davis Guggenheim’s “Waiting for Superman” and will produce Ron Howard’s film “Under the Banner of Heaven.”

Meanwhile, Sean’s new project “This Must Be the Place” premiered at Cannes Film Festival earlier this year and will hit theaters in December.

Enjoy the pictures of Sean Penn out with Shannon Costello (August 19).