A royal insider told The Sun, “They can also be a rather childlike family. I think it’s because they have to be so earnest in their public lives. Royals have always played in private. So William and Kate are really carrying on a long-held tradition.” The nicknames, said the source, are “done with affection usually and there are grains of truth about what one feels about another.” While students at St. Andrews, where they met and fell in love, Kate gave William the cheeky nickname “Big Willy” and he called his devoted girlfriend “Babykins.” (For a time, William referred to himself as “Steve” in an effort to blend in with other students.) William’s playful name for Kate was made public at the height of the phone-hacking court case in 2o13 when the now-defunct News of the World was found to have hacked into William’s phone back in 2006 and listened to his voicemail messages. After William and Catherine got married in 2011, their pet names for each other became a bit more sarcastic. According to The Sun, when William complained about his wife’s “endless mane of hair,” Kate returned the favor and teased him by starting to call him “Baldy.” The Cambridges reportedly love to tease each other. William had a jokey pet name for his wife in return and is said to have started calling her “DoD,” which is short for “Duchess of Dolittle,” referring to her lack of a career before they married.ae0fcc31ae342fd3a1346ebb1f342fcb Now that the couple is happily settled into married life, William and Kate’s nicknames for one another are once again more loving and playful. According to The Sun, in more privates settings, William has been overheard calling Kate “darling,” “babe,” and “poppet.” In happier times, Prince Harry reportedly had his own affectionate nickname for his sister-in-law: He called her “Cath,” a shortened version of Catherine. RELATED: For more up-to-date information, sign up for our daily newsletter. In recent years, William and Catherine have seemed more willing to show a bit of their personalities during official engagements. In 2016, while visiting an award-winning garden at the RHS Chelsea Flower Shower, Kate made the rare slip, letting her game face down for a moment when talking to her husband. According to Grazia, William asked Australian TV personality and landscaper Charlie Albone, “What [flower] is this one?” Albone replied: “That’s a Buxus.” Kate turned to William and said, “Babe, we’ve got those. We’ve got loads of those.”’ Landscape designer Mick Conway, who also attended the event, told Hello! that the duchess had actually called her husband “darling.” Whatever the nickname was, one thing is for sure: The Cambridges have no shortage of names—or affection—for each other. And for more on the future king of England, check out 27 Facts About Prince William That You Never Knew. Diane Clehane is a New York-based journalist and author of Imagining Diana and Diana: The Secrets of Her Style.