Speaking to EW, Witherspoon insisted that she and her How Do You Know co-star Paul Rudd were surprised when Obama recently requested to meet them.
"We went to the Oval Office, and there was Hillary Clinton having a meeting with Joe Biden. It was insane," she said. "When Obama came out and he turned to Paul and said, 'I loved you in I Love You, Man'. I grabbed Paul and I was like, 'Are you freaking out right now?' He's like, 'I'm freaking out!'"
The Oscar winner further remarked that she became flustered when the President asked why she and Rudd were in Washington DC.
She explained how she answered Obama's query: "We're doing a movie and... uh, I'm playing a character, who, uh... I'm working with Owen, uh... Owen… I could not remember Owen's last name. And Paul goes, 'Wilson!' like it was a party game."
How Do You Know is released on December 17 in US cinemas and January 28 in the UK.