Kate Middleton Furious Prince William Didn't 'Stick Up For Her More' After Prince Harry Shaded Mom-Of-3 In His Memoir: Source

Prince Harry's memoir certainly put more distance between himself and the royal family, but a palace insider claimed the contents of Spare also took a toll on Prince William and Kate Middleton's relationship.

As OK! reported, the Duke of Sussex shaded the Princess of Wales on several occasions throughout his tome, and she's grown increasingly upset that her husband hasn't snapped back at his brother for airing out the family's dirty laundry.

"Kate felt William should stick up for her more," the source explained to Radar. "Yet William and the palace thought that saying nothing was best."

In Harry's book, he alleged his sister-in-law caused Meghan Markle to cry during an argument prior to their 2018 wedding, and he also claimed both Kate and William found his Nazi costume scandal hilarious.

While the buzz over Kate and William's tension may be a surprise to fans, author Tom Quinn previously revealed it's very common for the parents-of-three to fight only when behind closed doors.

"Someone at the palace told me about the nicknames they have for each other. But it’s not all sweetness. They have terrible rows where they throw things at each other," he spilled to an outlet. "Kate might seem to be a very calm person, and William also. But it’s not always true. Because the big stress for William and Kate is that they’re constantly surrounded by [palace aides]. It’s like a Jane Austen novel."

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Quinn, who details their relationship in his new work Gilded Youth: An Intimate History of Growing Up in the Royal Family, said that despite the "shouting" matches, Kate is always able to smooth things over with her spouse.

"Kate is very much the calm one, William is the one who’s a bit hotheaded," he explained. "Kate is very level-headed. She’s the one who will pour oil on troubled waters and go, 'Let’s not stir things up.'"

"Kate has a way of de-escalating things with her Zen-like presence," an additional source shared. "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."