Even celebs get starstruck. Reese Witherspoon and Paul Rudd were speechless when meeting Barack Obama over the weekend.

The How Do You Know stars were touring the White House when they found out that the President would like to say hello. "We went to the Oval Office, and there was Hillary Clinton having a meeting with Joe Biden. It was insane," Witherspoon told Entertainment Weekly. "Then 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!'"

When Obama asked why the actors were in Washington, Witherspoon forgot co-star Owen Wilson's name. "'We're doing a movie and . . . uh, I'm playing a character, who, uh . . . I'm working with Owen, uh . . . Owen . . .'" she said. "I could not remember Owen's last name. And Paul goes, 'Wilson!' Like it was a party game."

How Do You Know, which also stars Jack Nicholson, opens December 17. —ISHITA SINGH