Bradley Cooper admits to feeling embarrassed by the fact he now calls Robert De Niro ''Bobby''.
The 'Hangover' star worked with the acting legend on new movie 'Limitless' and though he would find it "weird" to refer to his co-star by anything other than his nickname 'Bobby', he feels uncomfortable mentioning their Bond.
He said: "Unfortunately, yes, I do only think of him as Bob now, which is the most awful thing when you're watching people in interviews talking about 'Marty' or 'Bob' - you just want to throw up.
"But it would be weird for me to call him Robert."
Bradley, 36, recently admitted he can't stop mimicking De Niro since they worked together.
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.' "