Brad Pitt's A Heavy Drinker, Says Basterds Co-Star

Hmm, maybe this is something that's causing tension between Brad and Angelina?

Brad Pitt's Inglourious Basterds co-star Samm Levine tells Us Weekly that the actor can handle his alcohol ... and then some! "Oh, he's a fine drinking buddy," Samm spilled at Sundance on Wednesday. "Between Brad and Quentin, I would die of alcohol poisoning on day two if I had to keep up with those guys!" Yikes!

Samm added that he made fun of Jon Voight's accent in Anaconda, failing to realize that the man is essentially Brad's father-in-law! "So we had a great long conversation about that, and then I walked away, and thought, 'Jon Voight is kinda like his father, isn't he?'" Levine said. However, Brad took it lightly and Samm added, "[He's] just about the coolest guy ... everything rolls right off his back." Including those split rumors? I mean, Brangelina are on the cover of every major magazine this week...

So is Brad's drinking what's causing the trouble in their relationship? Or is it Angie's rumored cheating that's driving him to drink?