Taylor Swift Dragged Into Prince Williams' Royal War With Estranged Brother Harry After Concert Meetup: 'Everyone's Raving About Her'

Prince William cozied up to pop princess Taylor Swift knowing all too well his growing friendship with the Cruel Summer singer would set off the snubbed Duke and Duchess of Sussex — and palace spies say the unwitting superstar is caught in the middle of a royal civil war, RadarOnline.com has learned.

William, 42, beamed backstage in London as Taylor and her football player beau, Travis Kelce, snapped after-concert pics with the future king and his two oldest kids, Prince George, 10, and Princess Charlotte, 9. The "Shake It Off" songbird even shared one selfie online and wished Wills a happy birthday!

Taylor is very much on the royals' radar. It's not just Charlotte and George who love her. Everyone's raving about her and how talented and charming she is,” a source spilled, “The word is she's going to be top of their list for any upcoming galas or events that involve celebrities.”

Meanwhile, tipsters dish the devastated duke and duchess — William’s 39-year-old brother, Prince Harry, and American sister-in-law, Meghan Markle — are fuming over Tay-Tay’s tête-àtête with the heir to the throne — because the "Bad Blood" hitmaker has refused to give them the time of day.

The Sussexes caught Swift’s popular Eras Tour last August in California, where the duo settled after ditching palace life. But they weren’t invited backstage to meet the Grammy winner or sit with her squad in the VIP section.

And even before that, Taylor, 34, opted to shake off an offer from the former Suits stunner, 42, to appear on her podcast, Archetypes.

“It’s no secret Meghan went out of her way to try to build a relationship with Taylor and got nowhere, so it’s hard for her and Harry not to see this as being a calculated way for William and the royals to undermine them further,” the source snitched, “In their view it’s patently obvious the royals — and William in particular — love to go after anything they come close to having.”

Of course, the encounter wasn’t William’s first brush with the beautiful billionaire. More than a decade ago, he shared the stage with Swift as they joined Jon Bon Jovi for a rendition of the rocker's 1986 hit Livin' on a Prayer.

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"Meghan and Harry love Taylor's music," the source confided, "They've made it very clear they would love some sort of relationship with her."

"But now that William's made another big public connection with Taylor, any moves they make are bound to get labeled as cheap copycat attempts.

The mole insisted the pair doesn't begrudge the prince bringing his kids to the show — but explains, "It's the selfie that's set them off because it's just so out of the ordinary for the royals to publicize something like that. Even William's own fans have branded it as shade towards the Sussexes."

"Once again, they're feeling like the outsiders — and it hurts."