Brad Pitt and Sean Penn Don't Like Eachother

Tensions are running high on the set of Tree of Life. Brad Pitt, who took over Heath Ledger’s role in the adventure film after Heath’s death, is butting heads with co-star Sean Penn, 47. “They’re far from friends,” says an insider close to Brad, 44. “Sean is a bossy kind of guy, and that’s just not Brad’s style. He’s mellower. So spending time together has been a big challenge.”

Thankfully, they don’t have many scenes with each other. “A big theme in the movie is man alone in nature,” notes the insider. (That sounds really interesting!) “It’s not really a buddy film, and that’s probably for the best.” Their personality clash isn’t the only issue. “Sean is friends with Jennifer Aniston" says the insider. “Her short film in 2006, Room 10, starred Sean’s wife, Robin Wright Penn. They attended the premiere, cheering Jen on.”