HOUNSLOW, ENGLAND - MARCH 17: Prince William, Duke Of Cambridge, Colonel of the Irish Guards drinks a pint of Guinness next to Catherine, Duchess of Cambridge as they attend the annual Irish Guards St Patrick's Day Parade at Cavalry Barracks on March 17, 2018 in Hounslow, England. (Photo by Andrew Parsons - WPA Pool/Getty Images)
HOUNSLOW, ENGLAND - MARCH 17: Prince William, Duke Of Cambridge, Colonel of the Irish Guards drinks a pint of Guinness next to Catherine, Duchess of Cambridge as they attend the annual Irish Guards St Patrick's Day Parade at Cavalry Barracks on March 17, 2018 in Hounslow, England. (Photo by Andrew Parsons - WPA Pool/Getty Images)
HOUNSLOW, ENGLAND - MARCH 17: Prince William, Duke Of Cambridge, Colonel of the Irish Guards drinks a pint of Guinness next to Catherine, Duchess of Cambridge as they attend the annual Irish Guards St Patrick's Day Parade at Cavalry Barracks on March 17, 2018 in Hounslow, England. (Photo by Andrew Parsons - WPA Pool/Getty Images)
