Emma Watson was on hand to check out the London premier of "Harry Potter and the Half-Blood Prince" last night when a nasty incantation blew her frock to the side, exposing her dumble-drawers.
Oops! Where's the house elf when you need to him to keep these fancy dresses in place?
The 19-year-old - yes, sleazy Internet trolls, you can look without legal ramifications, but still feel shame - quickly got a handle on things, as usual, without raising her hand with the answer. With the wardrobe malfunction secured, she braved the London weather and thousands of screaming fans to take in the sixth movie in the series.
She even went on Letterman to talk about the incident, and her relative good fortune:
When Letterman pointed out the faux-pas on "The Late Show," a blushing Emma replied: "This was a small wardrobe malfunction that happens.
"At least I'm wearing underwear," the 19-year-old star added, before hanging her head in her hands to say she's "still learning" this stuff.
More on the premier after the jump ...
British actors Daniel Radcliffe, right, Emma Watson, centre and Rupert Grint arrive for the World Premiere of Harry Potter and the Half-Blood Prince, at a cinema in Leicester Square, central London, Tuesday, July 7 2009. (AP Photo/Joel Ryan)
Fellow stars Daniel Radcliffe, Rupert Grint and other cast members, along with the boy wizard's creator, J.K. Rowling, walked up a soggy red carpet before the screening in Leicester Square.
The film sees Harry and his friends at Hogwarts school battling evil Lord Voldemort -- and their raging teenage hormones.
Fans cheered the film's stars despite the weather, some holding placards reading "Harry, I'll be Your Chosen One" and "Britain Loves J.K. Rowling."
"I can't believe the dedication of the fans," said Tom Felton, who play's Harry's rival, Draco Malfoy, in the film.
Paul Taylor, 45, a nursing-home worker from Sheffield in northern England, came dressed in a tailor-made wizard's cloak and hat.
"It's quite exciting. You get caught up in all the energy," he said.
"I get quite involved with Harry Potter," he acknowledged. "I travel on steam trains and go to conferences."
Grint, who plays Ron Weasley, attended after recovering from a mild bout of swine flu.
He said the illness was not severe and "just like any other flu I've had before."
The cast members wore white ribbons in memory of Rob Knox, a young actor on the film who was stabbed to death in London last year.
"He would have loved to be here," said Jessie Cave, who plays Ron's sometime love interest, Lavender Brown.
The movie opens around the world July 15.
Two more films are in the works covering Rowling's final book in the series, "Harry Potter and the Deathly Hallows."