People reports that the relationship ended after Isabel was in a car crash with her intoxicated co-star Shia LaBeouf.

Apparently Adrian, 32, felt that he should be the car-bouncing with Lucas, 22, and not some drunken jackass.

"It wasn't working out," a source says. "Adrian saw her with Shia and that was kind of it—the crash, their hanging out. He obviously didn't appreciate it."

The couple reportedly called it quits three weeks ago. They had been dating for several months, according to reports.

Lucas' rep confirmed that the actress is "single." And looking for the next guy to drive her around drunk? Or perhaps the same one?