Kate Middleton's Wild Pub Confession About Prince William's Engagement — And the Family Reactions She Never Saw Coming

Catherine, Princess of Wales, became royal when she married Prince William on April 29, 2011. However, HRH decided to make history by telling her siblings in a local pub that she was betrothed to the future king.

"We sit in a corner, chattering quietly," James Middleton revealed in his new book Meet Ella: The Dog Who Saved My Life. "Catherine whispers the news and says it will become public in the next day or so."

"Pippa and I want to be visibly excited, but we have to tamp down our emotions so no one suspects a thing," he wrote. "We make a quiet acknowledgment that we’ll always be there for each other, look out for one another, support each other. No matter how crazy things get."

The Prince and Princess of Wales had one of the longest relationships in royal history before they wed in 2011 after a decade together. But William's "stubborn" streak frequently adds stress to the royal partnership, according to a source.

"Who doesn’t treat their husband like another toddler from time to time? It’s well known that William can be hot-tempered and certainly quite stubborn. Of course, they have rows, which apparently can be quite fiery, but they are quickly over and peace is restored," royal expert Jennie Bond told an outlet.

But unlike some of the horrific arguments William's parents, Charles and Diana, had when he was younger, his disagreements with Kate are not as dysfunctional.

"I think it’s a sign of a healthy and relatable marriage. And, actually, there is an incredibly equal partnership," Bond added.

Royal biographer Tom Quinn also spoke about the royal marriage to a publication by describing the Prince of Wales as being "prone to tantrums." He shared, "They do have rows. It's not a perfect marriage. They have terrific rows. But, where some couples have a row and throw heavy vases at each other, William and Kate throw cushions at each other. It's always kept under control."

It is very hard to see any of this strain since the future king and queen are so adept at displaying a positive and compassionate image while in public.

However, it is the "enduring bond" between Britain's next king and queen that is lasting, and also "inspires others."

"I wanted one day to experience what they were experiencing as a couple," James wrote. "Having been brought up... with strong, capable women surrounding me, I've enjoyed having this older brother-type figure to bounce questions [off of]. I’m just incredibly grateful that [Kate and William] have been supportive of me over these years as well."

The New York Post reported on James' book.