As the Duchess steals the show at another wedding, the sisters’ lifelong rivalry over who is “thinnest and prettiest” heats up.

Another day, another wedding for the Middleton sisters. But while Kate and her younger sibling Pippa once publicly basked in each other’s company, giggling and sharing in-jokes as they lapped up the attention, this time the mood had shifted. Witnesses at last week’s wedding of jockey Sam Waley-Cohen and Bella Ballin in Berkshire, say there appeared to be a rift, with Pippa shooting her sister cool looks as a rake-thin Kate stole the show in a gorgeous, recycled dress.

“Pippa seemed rather subdued,” reports one onlooker, “less herself.” Certainly, her frumpy lime coat and oversized hat shadowing her lovely face were a far cry from the stunning dress that saw her proclaimed “Her Royal Hotness” after Kate’s marriage to Prince William.

Childhood friends recall the sisters have always been close but competitive – and hugely so, according to Emma Sayle, who attended Downe House School with Kate. “There was always that thing of who could be the thinnest and who could be the prettiest,” Emma reveals.

Royal biographer Katie Nicholl agrees. “Certainly, when it comes to looks, like who is the slimmest or better-looking, there is a little friendly rivalry.” While both girls have been looking alarmingly thin in recent weeks, it was undeniably Kate who won the contest this time, the new Duchess of Cambridge upstaging Pippa – a delicious turn of the tables for Kate.

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