By Leah Ornstein - Breaking Celebrity News Style & Beauty Editor

Princess Kate's smoking hot sister Pippa Middleton was out and about in London on Friday, showing off her bombshell booty in tight spandex shortsduring her morning jog before changing into a perfect polka dot dress - and Breaking Celebrity News has the photos.

Her Royal Hotness, who is devoted to keeping her body in tip-top shape, left little to the imagination, flaunting her figure in skintight spandex running shorts, which she paired with a Nike shirt and her BVLGARI shades.