Kate Middleton, Meghan Markle Never Had A Relationship; Duchesses Very Different From Each Other: Royal Expert

Kate Middleton and Meghan Markle didn't have lots of things in common, according to a royal expert.

Middleton and Markle were often pitted against each other when the latter joined the firm. Despite the comparison, some were hoping they would be close friends since they were close in age and were both married to princes.

They never became BFFs, and according to a report, they were never friends in the first place. True Royalty TV co-founder Nick Bullen spoke with Fox News Digital and weighed in on the two duchesses' relationship.

"There wasn't really any relationship between the two of them," the royal expert said. "It was the brothers – Prince William and Prince Harry – who were falling out, not the sisters-in-law, not the wives."

Bullen, an award-winning documentarian who has produced programs about the royals for 20 years, added that despite Middleton and Markle putting on a united front in public, they didn't develop a close bond behind palace doors.

"I was talking to someone very early on in the Sussex marriage who had been at a dinner with Kate and had been asking about Meghan," Bullen claimed. "And Kate just said, 'She's just really different [from] the rest of us.' And not in a negative way. They just didn't have lots in common."

Bullen also shared things he noticed between Prince William's wife and Prince Harry's better half and pointed out their differences.

"Kate is sort of a well-to-do English girl who hadn't really had many jobs and had married her prince," he said of Middleton. "Whereas Meghan was a divorced career woman from LA. They're just different. So I think the relationship... was never really there as we, as the world, were hoping. We hoped it would be those shots of them going to Wimbledon together... [But] you'd be hard [pressed] to find moments when it was just the two of them coming together."

International Business Times could not independently verify the claims.

Historian, writer and broadcaster Tessa Dunlop also weighed in on Middleton and Markle's bond. She told OK! magazine that the sisters-in-laws' relationship is "frosty, but it's polite."

Dunlop also said they were very different and even described them as the "inverted versions of each other."

"Kate's values were deference, appropriate levels of self-possession within a system, don't rock the boat, you make change through embracing the institution almost, the paradox. Meghan's the other way around. They're totally like inverted versions of each other," the "Elizabeth and Philip: A Story of Young Love, Marriage and Monarchy" author previously said.

According to her, Middleton is a "well-mannered girl," and she's not the type to dish others' dirt. Meanwhile, Markle grew up in a competitive environment in Hollywood.

"But it's a very different environment. Hollywood is about climbing over other people to get that role, to get the gig, to improve the rating to be better than the next one -- that's ambition. But Meghan came from the outside, a hostile culture, and it [royal life] must have seemed quite alien," Dunlop said.