Kate Middleton

The Royal Grape! With first-trimester morning sickness woes long behind them, the expectant Duke and Duchess of Cambridge are relishing in the joys of Kate Middleton's first-ever pregnancy -- and, of course, their growing little one, who is due in July. Indeed, in the latest issue of Us Weekly, out now, a royal insider says that Middleton, 31, and Prince William, 30, have a hilarious nickname for the baby-to-be.

"Kate and William call it 'our little grape,'" the insider says, explaining that they came up with the fruity moniker after noting the size of the fetus on a recent growth chart.

Although the Duchess has noticeably kept up with her official royal duties, she's also kept up a more private daily routine: A brisk walk on the palace grounds, a jaunt to a local Starbucks for a decaf coffee -- and something sweet!

"She's got sugar on the brain," another source says. "Chocolate, biscuits, cake." First-time dad William, meanwhile, carves out as much time as possible to be with his wife of nearly two years, clocking out of his grueling 24-hour shift as a search-and-rescue pilot to be by her side. "They make it work as best they can."

For much on how the royal couple are prepping for baby -- and what real names they're thinking of for the tyke -- pick up the new Us Weekly, on stands now!