It's a fashionista's worst nightmare – turning up to an event in exactly the same dress as another guest.
So we can't imagine Nicky Hilton and Tommy Hilfiger's wife Dee Ocleppo were best pleased when they attended a Valentino party on Monday night wearing the same frock.
The ladies both looked stunning in the striking dress
It's not exactly a subtle number either – a pale blue, floor-sweeping gown with intrícate embellishment in mustard yellow and red from Valentino Resort 2016.
But the ladies didn't actually seem to mind the faux pas, greeting each other with a warm kiss on the cheek as they spotted their identical dresses.
The ladies' dress situation didn't go unnoticed among the other guests at the Valentino bash.
Mark Ruffalo, the star of Avengers: Age of Ultron, was seen laughing with the duo as he pointed out their dresses.
Keira Knightley opted for simple chic in an all-black ensemble
Nicky was attending the bash with her mother Kathy Hilton, while Dee was on the arm of her fashion designer husband.
The ladies rubbed shoulders with a host of fellow famous faces at the party, including Kiera Knightley and Diane Kruger.
Diane dazzled in this stunning sequin gown
Keira, who is a new mum after giving birth to her daughter Edie earlier this year, was elegant in a long black dress with a matching cape.
Diane, meanwhile, added a touch of sparkle to proceedings with a black, gold and green sequin embellished dress with a plunging neckline.