certainly lives the champagne lifestyle. But as she cruised around the French Riviera on a yacht called Serenity yesterday, she cradled a tumbler of what looked like chilled white wine.
The blonde model, who originally hailed from Croydon, drank from the large glass and smoked her way through a pack of cigarettes as she soaked up the sun with a group of friends.
At one point she even took a bite from an ice cream - just the one though - she is a supermodel, after all.
Kate, 35, wore a retro denim and red gingham bikini, accessorised with a large diamond on her right hand.
She then topped up her tan by pulling off her bikini top in favour of a sarong, while her female friends were equally relaxed about stripping off.
The group included Yves Saint Laurent designer Stefano Pilati, who photographed the topless sunbathers onboard the yacht.
Kate then got behind the lens to snap some shots of her friends, before they laughingly admired her handiwork.
The model and rocker boyfriend Jamie Hince, guitarist for The Kills, later embraced as they enjoyed a dip in the sea.
Kate and Jamie are on holiday with a large group of friends, and Kate's six-year-old daughter Lila Grace.
But like many a celebrity family, they have been joined by an assistant and two massive bodyguards — who appear to be on babysitting duty for Lila.
Earlier Kate and her entourage dropped into Saint-Tropez for a spot of shopping.
Her group tried to blend in with locals and holidaymakers, but as they wandered into the port-side café Le Senequier, they still managed to attract attention.
It wasn't Kate's tiny hotpants and long legs that turned heads though.
Jamie and Kate drew attention after they appeared to squabble about where to sit.
Although friends say the couple are still happy, sources have revealed they are often bickering.
A recent argument was caused after Kate draped a rabbit skin throw over their bed.
A friend told the Mirror: 'Huge conflict has flared up between the pair over what Jamie claims is Kate’s disregard for animal welfare.
He is a strict vegan who won’t even touch cow’s milk and is horrified by Kate’s insistence on wearing fur and having it around the home.'
They added: 'Their argument ended pretty abruptly with Jamie storming off, calling Kate a "cow killer".'