What does one wear to a fancy fashion party hosted by Valentino and held at the Guggenheim Museum in New York City? If you're Julia Fox, the answer is your underwear, duh.

Forget ball gowns and OTT accessories. The model/actress/author and mother (in every sense of the word) instead donned a simple white vest top featuring a white satin strapless bra with lace cups overlaid onto the ribbed fabric to DJ at the A-list event celebrating Cult100, the annual list published by Cultured Magazine that recognises 100 individuals who are shaping culture across the fields of art, film, literature, food, fashion, and more.

Julia paired the top with white knickers decorated with a pointelle butterfly pattern to perfectly nail the underwear-as-outerwear trend. Safe to say she certainly made a statement with her choice of attire.

julia fox bum cut out knickers valentino celebrates the cult100 at guggenheimpinterest
WWD//Getty Images

So far, so standard for Julia. But of course, her 'fit obviously featured a twist...

julia fox bum cut out knickers valentino celebrates the cult100 at guggenheimpinterest
WWD//Getty Images

Turning around, Julia revealed her knickers featured a giant cut-out that covered the majority of the back of her pants. Edged in a frilly trim, the bum-crack framing cut-out flashed the sheer nude tights she had on underneath as well as the majority of her derrière. Now that's so Julia!

julia fox bum cut out knickers valentino celebrates the cult100 at guggenheimpinterest
WWD//Getty Images

This is far from the first time Julia has opted for such a cheeky ensemble. Last month, she attended the Mother, Daughter, Holy Spirit runway show – a fundraising event for the Trans Justice Funding Project – in a pair of jeans that laced entirely up the back. Julia went commando in the risqué denim, flashing her bum cleavage in the process.

Everyone's clicking on...

julia fox commando lace up bum jeans mother, daughter, holy spirit fashion showpinterest
Roy Rochlin//Getty Images

It's a look she first tried out all the way back in June 2022, wearing a grey Alejandre coordinating crop top and cut-out, lace-up cargo trousers set.

julia fox bum cleavagepinterest
Rachpoot/Bauer-Griffin//Getty Images

She went on to up the ante in October 2023, donning a pair of black leggings with a heart-shaped cut-out at the butt.

julia fox bum cutout leggingspinterest
Shutterstock

Similarly, in December 2024, she replicated the look in a Catholic Guilt chainmail dress crafted from hundreds of thousands of jump rings that took 700 hours (!!) to hand-weave together and featuring a bum cut-out.

julia fox chainmail dress butt cut outpinterest
Wendell Teodoro//Getty Images

Other celebrities haven't jumped on the trend in quite the same way, preferring to stick to more classic takes on naked dressing. Not that Julia cares – she wears what she wants and that's exactly why she's a fashion icon.

Follow Alex on Instagram.


Headshot of Alexandria Dale
Alexandria Dale
Digital Fashion Writer

Alexandria Dale is the Digital Fashion Writer at Cosmopolitan UK. Covering everything from the celebrity style moments worth knowing about to the latest fashion news, there’s nothing she loves more than finding a high street dupe of a must-have designer item. As well as discovering new brands, she’s passionate about sustainable fashion and establishing the trends that are actually worth investing in. Having worked in fashion journalism for six years, she has experience at both digital and print publications including Glamour and Ok!