Adrian Grenier and girlfriend Isabel Lucas have broken up according to People.com. Isabel Lucas was a passenger in Transformer's star Shia LaBeouf's truck when he was involved in rollover accident in Hollywood and suspected of DUI.

The pair broke up about three weeks ago, right after the accident that left LaBeouf with a crushed hand. "It wasn't working out," says a source. "Adrian saw her with Shia and that was kind of it - the crash, their hanging out. He obviously didn't appreciate it."

The break up doesn't seem to slowing Adrian down though. We spotted the Entourage star getting a stand-up paddleboard lesson in Malibu, CA today with a two gorgeous brunettes. The shirtless star looked like he was having a great time, especially with the gorgeous girl in the black shirt. The two hugged and held hands after exiting the water.

Does Adrian already have a new lady?