Madonna left little to the imagination as she arrived at the Met Gala in a lacy black dress exposing her buttocks and barely covering her breasts.
The Queen of Pop, 57, posed on the red carpet in the revealing outfit at one of fashion's biggest events of the year, dubbed the Oscars of the East Coast.
Beyonce also created a stir, attending the New York gala alone in a pink latex gown by Givenchy.
She has faced rumours of marriage problems with her husband Jay Z following the release of her new album Lemonade, which contains lyrics about infidelity.
British actress Emma Watson donned a black and white bustier, trousers and train - and revealed she was actually wearing plastic bottles.
Watson's statement ensemble, created in collaboration with Calvin Klein and Eco Age, was crafted from yarns made from recycled plastic bottles, as well as organic cotton and silk.
She told her 32.8 million Facebook followers: "Plastic is one of the biggest pollutants on the planet. Being able to repurpose this waste and incorporate it into my gown for the ?#?MetGala? proves the power that creativity, technology and fashion can have by working together."
The event celebrates the Metropolitan Museum of Art's new exhibit, Manus x Machina: Fashion in an Age of Technology, which provided the gala's theme of the convergence of man and machine.
Rapper Kanye West attended in ripped jeans and a sequinned jacket, completing his look with blue contact lenses.
He struck a casual look next to his wife, reality star Kim Kardashian, who wore a floor-length silver gown split to the top of her thigh.
West wrote on Twitter: "thank you Olivier for making 4 dresses for Kim to choose from which we chopped 2 in half. and thank you for turning my personal jean jacket into a couture piece ... We just had fun with the "future" theme !!!"