Ever since Kate Middleton gave birth to Prince George, she and Prince William have been spending quality family time together. Most recently, they've been vacationing in Scotland, at Balmoral Castle, the queen's traditional vacation home. The Duke and Duchess of Cambridge are joined in Scotland by the queen, Prince Philip, Prince Charles, and Camilla, Duchess of Cornwall, as well as their newborn son, Prince George. With their latest holiday in mind, we're taking a look at the royal family's best off-duty moments — from slipping into bikinis on exotic vacations to hitting the polo field with their relatives and pals. Click through to see how Kate, William, Prince Harry, and the rest of the royals let loose when they aren't making official appearances.