"Kate felt William should stick up for her more," a well-placed palace insider dished. "Yet William and the palace thought that saying nothing was best."
Insiders said that Kate and William have resorted to trading insults, name-calling, and slamming doors during their private marital spats, but in public they have chosen to always remain poised and committed to their duties.
Excerpts from an upcoming book hitting shelves in December detailed how their relationship isn't always picture-perfect.
"It's not all sweetness," according to Tom Quinn, author of Gilded Youth: An Intimate History of Growing Up in the Royal Family. "They have terrible rows."
"The big stress for William and Kate is that they're constantly surrounded by palace aides," Quinn penned. "When he gets annoyed with Kate, his aides can tell by the way he talks to her."
Sources claimed the Princess of Wales was not only upset that William and King Charles chose to stay mum about Harry's book, but also embarrassed that William's contentious showdown with his brother made it into the pages.
Harry wrote that William allegedly threw him on the floor as they argued over Meghan Markle in November 2019.
William was said to have called the former Suits star "difficult," "rude," and "abrasive," and the Duke of Sussex fired back, claiming that sounded like a line from the "press narrative."
The Royal Observer learned that Kate hopes her husband of nearly 12 years "learned a lesson about keeping his temper in check."
William and Kate tied the knot back in April 2011 and despite going through hardships together, both do their part to avoid squabbling in front of their kids, insiders claimed.
"Kate has a way of de-escalating things with her Zen-like presence," a source said, adding that divorce is not an option. "When William and Kate got married, they took their vows to heart. They are proud of their marriage, and they both want to see it last."