The actor invited his celebrity friends, including P. Diddy and Harvey Weinstein, to the gathering after the premiere of his new movie 'Killing Them Softly', reports a website.
"Brad was on top form, having a proper knees-up with the boys. It was like a super-sophisticated bachelor party. They were all drinking bottles of whiskey and puffing away on cigars," said a source.
"Guests were driving around the villa grounds on little buggies which came complete with two butlers. Film heavyweight Harvey Weinstein was telling everyone, 'What else are you going to do in Cannes but throw a big party and party hard?'," the source said.
"P. Diddy raised a glass to Brad over his engagement to Ange and then invited the whole party back to his yacht," the source added.