"I thought, 'Y' know, just remember you've hired me... I'm, like, the G-rated actress," the Daily Express quoted her, as saying.
However, the actress has revealed that the saucy scene wasn't the only uncomfortable moment for her - she had to kiss co-star Clive Owen in front of her cameraman husband Danny Moder.
"It's awkward... When you're not kissing your true love, it's awkward," Roberts said.