Olivia Wilde's post-baby body was on the David Letterman show earlier this week. The new mom is just 7 weeks since giving birth to her first son, Otis Sudeikis, according to the Hollywood Life and she looks fantastic!

Olivia Wilde talked about how awkward it was to run down a set of stairs completely in the nude on The Late Show on Wednesday for her new movie 'Third Person.' The 'Drinking Buddies' star plays Anna in the Paul Haggis-directed movie about three overlapping love stories that take place in New York, Paris and Rome. In the movie, which was shot before she gave birth to Otis in April, Wilde appears naked.

Wilde took the opportunity to reminisce on what her body was like before she and husband Jason Sudeikis welcomed their son Otis on April 20.

Wilde said, 'It's great now that I've had a baby because I can look at it and be like, 'yep, that was once the way it was,'' the star quipped about her naked body in the movie.

'But its funny because we shot it in Italy,' she continued, 'and for them being naked in no big deal.'

When Letterman pushed further to find out exactly 'how' it was that Olivia executed those naked scenes, she came back and held her own.

""Not only did I have to do it again and again and again, but this was a scene in which I was running down stairs naked, which no one should ever do on camera," she said. "And I noticed that had been strategically removed from the film, which I approve of. That's great ... It's not great dressed, now that I think about it, but naked it's bad. There's things that no one should see. The body does things that it's not supposed to ... and it's jiggling. Moving."

Wilde then offered, 'Do you want me to re-enact it?' and pretended to stand up to get into position.