The Duchess of Cambridge, Kate Middleton, has long been rumored to be feuding with her husband Prince William’s grandmother, Queen Elizabeth II, and a new report alleges even more trouble in their tumultuous relationship.

In the Feb. 23 issue of Life & Style Magazine, the tabloid claims that the queen is upset with Kate’s brother, James Middleton, following his recent interview with a British magazine called TYD (The Young Director). The 27-year-old entrepreneur — who used the interview to promote his gourmet marshmallow company — admitted that being a sibling of Kate’s can be “frustrating.” According to the magazine, the 88-year-old monarch feels his remark was disrespectful to the royal family.

“She is furious. Queen Elizabeth is the one who is frustrated with how the Middletons seem to moan about the royals all the time. She thinks its tacky," an insider asserted. “The queen feels angry and let down.”

According to the magazine, the queen has even demanded Kate speak to her family about her concerns. “She’s told Kate to warn them not to talk about the royals or Kate in any other interviews ever again,” said the source. 

Middleton Family Pippa and James Middleton, siblings of the Duchess of Cambridge, at the Diamond Jubilee Pageant in London, in 2012. Photo: Getty

The queen is said to be especially upset about James’ comments, especially considering she invited the Middletons to her Sandringham estate over Christmas. It was previously rumored that Elizabeth was not in favor of having them visit her home during the holiday season. “It makes James look ungrateful and rude,” said an insider. “It really irks the queen. She has gone out of the way to make the Middletons feel welcome. … It will be a long time before she welcomes Kate’s family around to tea again.”

James is said to be just the latest Middleton to upset Queen Elizabeth, but he may not be her top target for much longer. Life & Style notes that the actions of Kate’s 31-year-old sister Pippa, and her parents, Carole and Michael Middleton, may have also caught her attention. While Pippa used her newfound fame following her show-stopping appearance at William and Kate’s 2011 wedding to try to secure a gig with NBC, the magazine reports that Kate’s parents have cashed in on “royal-themed” products for their company Party Pieces.

Let’s hope the Middletons and the Windsors can put their differences aside for the sake of William and Kate. Kate, 33, is due to welcome their second baby — to join 17-month-old Prince George — in April.