Spears and Letterman on Nov. 6
Britney Pops In on a Surprised David Letterman | Britney Spears
Britney Spears played it for laughs on Monday night's Late Show with David Letterman.

Sporting a blonde bob and a short black dress that showed off her newly svelte shape, the new mom – whose second son, Jayden James Federline, was born Sept. 12 – surprised the host by walking onstage behind him as he was sitting at his desk.

"Oh, my god," he exclaimed, standing up to shake her hand and plant a kiss behind her ear. "Hi, how are you? Nice to see you. Oh, you look wonderful."

"Thank you so much," she said. "I'm in town, and I'm just such a huge fan. I had to stop by."

"That's very nice of you to say," said Letterman. "That means so much to me."

Said Spears: "Uh, no, I wasn't talking about you. I was talking about Will Ferrell."

A flustered Letterman then quickly directed her to the whereabouts of his guest for the evening: "In the green room."

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