Royal bridesmaid Pippa Middleton is following in her sister's noble footsteps -- she is dating a mega-rich earl whose real-life home is the castle used to portray Hogwarts in the "Harry Potter" movie series.
Middleton, 27, is in a serious romance with her old flame George Percy, heir to the Duke of Northumberland.
It is one of Britain's richest and grandest dukedoms, with a vast estate that includes Alnwick Castle, the movie setting for Harry Potter's wizard school.
Percy, 27 -- dubbed "Prince of the North" by pals -- will one day inherit the lot, including a fortune of $500 million.
A source close to the couple said Thursday night, "George is very smitten and completely in love with her. It looks like the Middleton sisters will be completing the double before too long."
Middleton has been close pals with Percy for years. They met at Edinburgh University and had a fling in their final year, in 2008.
Last year, they insisted they were "just friends" after he was seen helping her get over her split with banker Alex Loudon.
But it blossomed into love at a New Year's Eve party thrown by the Middleton family.
The source revealed, "Pippa sat herself next to George at supper and made sure she was hanging off his arm all night. And then she made her move."
"It was like a shark circling its bait," the source added. "Some people think she has always set out to do this."