A source is giving an insight into how Kate Middleton supposedly feels following the release of “Spare.” It comes as Prince Harry made bombshell revelations in his newly released memoir, including “private matters.”

Speaking to Entertainment Tonight, a royal insider stated that the future Queen Consort is “hurt and disappointed.” As explained, she feels these things because she believes her brother-in-law made some “private matters” public with his highly anticipated book.

The said disappointment of the Princess of Wales is reportedly further accentuated as the Duke of Sussex had always described her as the sister he never had. Also, it is noted that he acknowledges in his book that the relationship between his sister-in-law and his wife, Meghan Markle, never took off.

In “Spare,” Prince Harry details the tension-filled relationship between Meghan Markle and Kate Middleton.

Page Six noted that at one point in the book, the former working royal recalls what happened between his wife and sister-in-law days before their 2018 wedding, involving the infamous bridesmaid dresses. He is said to have revealed that he later found the former actress in tears “on the floor” following the rift.

The Duke of Sussex also alleges that the Duchess of Sussex was reprimanded for telling the Princess of Wales she “must have baby brains because of her hormones” after giving birth to her youngest child with Prince William, as per the outlet.

But, aside from the serious subjects, the royal-born Prince does not reportedly seemingly stop the criticisms there as he also shines a light on the mundane things.

Meanwhile, royal author Tom Bower also told Page Six that Kate Middleton is “outraged and hurt” due to the allegations Prince Harry made against her in his newly released memoir.

The “Revenge: Meghan, Harry and the War Between the Windsors” author deemed the attacks toward the British Royals “grotesquely gutter” and “disgraceful,” as well, in the same exchange, published earlier this week.

The expert then noted to the publication that the “deception” of the Duke of Sussex was "just unbelievable," adding that he was “at the Queen’s funeral knowing what he’d written about Kate and William and his father, without giving a hint of what was to come.”

Kate Middleton and the rest of the British Royal Family remain silent about the matter. They are not commenting on the memoir, along with the claims from Prince Harry.

But, last week, royal expert Katie Nicholl told Entertainment Tonight that Prince William is also “incredibly angry at the level of detail” his brother has shared in his material.

She added that the future King is “upset,” as well, because King Charles III made efforts to extend an olive branch to the Sussexes numerous times, but the pair has refused the good gestures.