Clooney, Brad Pitt, Matt Damon and Andy Garcia, shooting back-of-the-house office scenes for "Ocean's Thirteen" at Bellagio on Wednesday.
That's not to say he [Pitt] isn't having a blast with his costars. "These guys are amazing together," says one set source. "It's like they've never been apart. They're working hard, but they're having a lot of fun making the movie."
Says another on-set observer, "it's been like coming back from summer vacation and being with your friends. Just guys out there having fun."
Still, that fun doesn't include much after-hours carousing for the newly family-oriented stars (Damon, like Pitt, is a new father – he and wife Luciana welcomed daughter Isabella in June, and he's stepdad to Luciana's daughter Alexia, 8). "They have a great time working together," says a source, "but they're on the set at 5:30 in the morning."