Kate Middleton stoked royal feud rumors at Prince Harry and Meghan Markle's wedding on Saturday with her bizarre body language with stepmother-in-law Camilla Parker Bowles!

As Middleton, 36, sat next to Camilla, 70, in their pew at St. George's Chapel in Windsor Castle on May 19, onlookers picked up on tense moments between the two.

Middleton, who is married to Camilla's husband Prince Charles' son William, 35, was first seen having an intense conversation with her.

Then, although Camilla's face was largely covered by her oversized fascinator, people noticed that she was murmuring something quietly when Middleton shot an exasperated "side eye" look at her during the ceremony. It appeared that Camilla had gotten on her step-daughter-in-law's nerves during the royal wedding!

Also, Camilla got criticized for looking like she was laughing when Harry and Markle's U.S. Reverend, Michael Curry, made an emotional speech which spoke about slavery, the Old Testament and quoted Dr. Martin Luther King Jr. during the wedding.

But Twitter users particularly went wild about Middleton, who unveiled her post-baby body at the wedding, apparently dissing Camilla with her eyes. Body language expert Susan Constantine told Good Housekeeping, "We typically don't see such serious and stern behavior from Kate. This gesture—smirked eyes and a turned down mouth—was a rather dignified way to reprimand Camilla."

As RadarOnline.com has previously reported, in his book Game of Crowns, author Christopher Andersen claimed that Camilla schemed to sabotage Kate from stealing the spotlight.

RadarOnline.com also exclusively learned that Camilla dislikes Markle as well! "Camilla simply cannot believe what an easy entree she’s getting" into the royal family, a palace insider told RadarOnline.com of Harry's new wife.

Queen Elizabeth, 92, reportedly called Camilla a wicked woman for splitting up her son Charles, 69, and the late Princess Diana, according to a biographer. But Charles married Camilla in 2005, years after Di's tragic death, nonetheless!