As millions of couples around the world celebrate Valentine's Day today, Prince William and Princess Kate are surely joining in the romance of the loved-up holiday. More than 21 years ago, the rumours of a blossoming relationship between William and his university housemate, Kate Middleton , were finally confirmed, when they were snapped together looking blissful on a Swiss skiing holiday in April 2004. Fast forward two decades, the pair have now been married for almost 15 years, have three