After shooting a movie with demanding action scenes, it's tough not to bond with your costar -- especially if she's Jennifer Aniston.
"I literally became a member of her family," Gerard Butler told PEOPLE of his Bounty Hunter costar at their film's London premiere Thursday night. Just don't confuse that closeness for something romantic. "I went down for her birthday in Mexico," Butler said. "Of course, everyone takes that as something else, but we are very good friends."