Charlene Wittstock's infamous 2006 "Mermaid" dress, as dubbed by the European press. Photo: Getty Images

Think life's a fairy tale for Monaco's future princess, Charlene Wittstock?

Don't bet your tiara on it.

Despite her 3-carat Maison Repossi engagement ring, Grace Kelly good looks and the affections of formerly fickle Prince Albert of Monaco, Wittstock says she's says her new role hasn't always fit like a royal glove.

The fetching princess-to-be confesses she's clueless about fashion and has inspired jealously in the tiny municipality.

The 32-year-old South African is set to marry the 52-year-old son of the late Prince Ranier and American actress Kelly in July 2011.

The former Olympic backstroker tells the UK's Tatler magazine that all those years spent logging laps washed up her fashion sense.

"I was used to living in a bathing suit and totally clueless about fashion," she tells the mag, which features her on a beguiling December cover.

In 2006 Wittstock was dubbed "Albert's Mermaid" by the European press when she attended a Red Cross Ball dressed in a green sequins halter gown. The sports-loving Wittstock explains she rushed to get ready after a day of beach volleyball. "I borrowed a green dress from a friend, fixed my hair myself and painted my nails red. I looked like a Christmas tree."

And if that's not bad enough, Wittstock says finding acceptance amongst Monaco's jet set has taken time. She has only made two "real friends" in Monaco during her 10-year relationship with the prince and "of course, I've been subject to jealousy, but that comes with the territory."

The jealousy is bound to get worse when royal watchers get a peek at her Tatler debut: Wittstock was photographed dripping in diamonds and looking completely regal in a white gown and tight bun on the mag's cover, set to hit newsstands this week.

Speaking of Monaco's royal family, read why StyleList readers consider Grace Kelly the most beautiful American woman ever.