updated 05/16/2010 AT 4:00 PM ET
•originally published 05/16/2010 AT 5:30 PM ET
While Wall Street: Money Never Sleeps stars Shia LaBeouf and Carey Mulligan huddled affectionately nearby on Friday in Cannes, director Oliver Stone couldn’t help but reflect back to watching the two fall in love on set.
“It was all thanks to me,” Stone told PEOPLE, laughing, of the young costars’ “amazing and wonderful” romance during a lush party in the hills above Cannes, following the film’s premiere.
“You could see their chemistry right away, and it was pretty powerful,” the director said. “They were completely professional on the set, but there was no mistaking what was happening.”