In a surprising move, Kate Middleton, the Duchess of Cambridge, broke from tradition at Queen Camilla's coronation on May 6, raising eyebrows among those present. Observers at Westminster Abbey were taken aback when Middleton, usually known for her adherence to royal protocol, deliberately avoided a customary curtsy to the newly crowned queen.

A source close to the situation shared with Radar that this apparent act of defiance was a clear reflection of the Duchess' displeasure with some of the decisions made around the coronation. "The snub was no accident. Kate was evidently upset over the directives about coronation guests issued by Camilla," the insider said.

What stoked the fire was an imbalance in the number of family members allowed at the momentous occasion. Camilla, enjoying the privilege of the crown, had invited 20 guests while Middleton was permitted only four. To further add to the drama, Rose Hanbury, a long-standing friend of Camilla and alleged past romantic interest of Prince William, was among the invited.

"Even though the accusations about William's affair were fervently denied, the allegations had left a lasting scar on his marriage with Kate," the source pointed out. "Camilla's invitation to Rose was a blatant provocation."

The insider further claimed that the Duchess of Cornwall's envy towards Kate had been simmering ever since the latter's entry into the royal family, leading to a series of subtle confrontations over the years. Despite maintaining a calm public image, Kate is "anything but a pushover when it comes to palace politics."

Tensions between the two women are expected to surface more prominently, especially following the passing of Queen Elizabeth II. Prior to her demise, Kate had largely suppressed her feelings towards her stepmother-in-law, revealed the source.

Camilla's controversial past, most notably her affair with King Charles which eventually led to his divorce from Princess Diana, continues to stir the royal pot. Prince Harry, in his memoir, expressed his disapproval of Camilla, even alleging her involvement in spreading negative press about him and his brother, William.

Despite Harry's harsh words, Fiona Petty-Fitzmaurice, Marchioness of Lansdowne, stated that while these accusations have indeed "caused Camilla some discomfort," she remains steadfast. "She doesn't allow it to get to her," she stated.