Bradley Cooper can't stop mimicking the mannerisms of Robert DeNiro ever since the pair appeared together in new movie 'Limitless'.
The actor appeared alongside the screen legend in new movie 'Limitless' and admits he couldn't help but copy his co-star's mannerisms - even when they had finished working on the film and he had started shooting 'The Hangover 2'.
Bradley said: "It's like osmosis. You can't be around that guy without starting to take on his mannerisms. And I started to worry that during the scenes that I had with him I'd start doing him - to him - in the scenes. Not even consciously.
"So much so that when we started filming 'Hangover' part two - like when we're in Bangkok and I'm talking to Alan, and he's like 'Cut! Dude, you're doing De Niro.' I'm like, 'I know, it's crazy.' "
The 36-year-old star also promised the forthcoming 'Hangover' sequel will be "epic".
Asked what fans can expect, he said: "You know, I think it might be epic. I think it might be a big one. I think.I shouldn't say - I've got to stop saying that."