What were they thinking?
And who let them out of the house (under) dressed like that?
These are usually not the questions that come to mind at the fashion industry's version of the Oscars, but this year was an exception.
Polish model Anja Rubik didn't leave much to the imagination when she walked down the red carpet wearing slinky silk strips of cloth that barely covered her chest.
But that was not the talking point at the annual Metropolitan Museum of Art Costume Institute Benefit in New York on Monday.
Better known as the Met Gala, it is the biggest night for the fashion world, where fashion's top names come out to mingle on the red carpet with the most glamorous stars on earth.
This year's swish shindig celebrated the careers of Italian icons Miuccia Prada and Elsa Schiaparelli with the opening of the Schiaparelli And Prada: Impossible Conversations exhibition.
But all eyes were on Rubik as she worked the red carpet in a pose that paid tribute to Hollywood actress Angelina Jolie at this year's Oscars.
However, it wasn't just the aggressive leg-out stance that made photographers go trigger-happy.
The 28-year-old Victoria's Secret model's champagne-coloured Anthony Vaccarello dress had a slit so high and wide that her left hip bone - and obvious lack of underwear - was on display.
It would have been right at home at the Grammys or MTV Video Music Awards, but the sophisticated Met Gala?
We're not so sure.
But Huffington Post commented that Rubik is starting a new trend.
"Are hip bones the new cleavage?" it wrote.
"And there's no way she's wearing underwear with that, right? Just sayin'."
While Rubik deserves an award for the most eye-popping dress that night, she was not the only woman flaunting more flesh than we are used to.
Beyonce never fails to make an entrance and it was expected for the US pop diva to show up in a statement outfit - and then some.
Post-pregnancy bod
The 30-year-old flaunted her curvy post-pregnancy figure in an ostrich feather-trimmed Givenchy Couture gown that made her look stunted.
The outrageously sheer garment with strategically placed embroidered detailing also revealed too much booty for one's liking.
Wrote US TV show E! Fashion Police: "It reeks of 'I got my body back' desperation. Sorry B, save it for the mommy-makeover magazines and get back in touch with your classy self!"
On the other hand, Gwyneth Paltrow, 39, demonstrated how to pull off a peek-a-boo with style.
The leggy Hollywood actress, known for her minimalistic elegance, unexpectedly offered a generous amount of "side boob" in a shiny Prada mini.
Others who were decked out in bewildering fashion included US actress Elizabeth Banks, who couldn't decide if she was there to promote The Hunger Games or her upcoming chick flick, What To Expect When You Are Expecting.
The 38-year-old not only channelled her wildly dressed The Hunger Games character Effie Trinket in a Mary Katrantzou outfit, the floor-length gown came with a peplum so protruding that it made her look nine months pregnant.
Talk about killing two birds with one stone.
You would think that professional models would know best how to strut their stuff and stand apart from the crowd.
However, 23-year-old Canadian model Coco Rocha took that to the extreme by showing up in a vintage canary yellow Givenchy pantsuit that was once owned by the late screen icon Elizabeth Taylor.
But we bet Taylor would not have paired it with a bright pink top and matching hair extensions.
Then there was Christina Ricci, whose pink and black Thakoon gown came with a gigantic bow set upon her back.
It was a bold choice worthy of the Met Gala and the 32-year-old did her best to work all that fabric, but sadly, it swallowed the petite US actress whole.
Perhaps the one attendee who took the cake was US designer Marc Jacobs, 49, who professed his love for Comme des Garçons dresses at his Fall 2012 presentation in March.
He already went overboard wearing a sheer black lace Comme des Garçons dress, but did we really need to see his visible white boxer shorts underneath?