Casiraghi confirmed her relationship with Dimitri Rassam with her dress choice at Monaco's Bal de la Rose
Rose Ball 2017 To Benefit The Princess Grace Foundation In Monaco
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Only a few days after Spanish and French tabloids published the first pictures of Charlotte Casiraghi and her new boyfriend Dimitri Rassam, Casiraghi seemed to confirm her relationship — with her fashion choices.

Princess Caroline‘s eldest daughter attended Monaco’s annual Bal de la Rose on Saturday (unescorted). For the event, Casiraghi, 30, wore a vintage black velvet dress, which several sharp-eyed royal watchers recognized: It was the exact number her mother previously wore to a high-profile Monaco event that she had attended alongside Rassam’s mother, Carole Bouquet, in December 2000.

Consider the dress a subtle wink. Photos of the 2000 event confirmed Casiraghi’s dress as identical to one her mother, Princess Caroline, wore onstage at awards ceremony that she organized and actress slash model Bouquet hosted.

Nijinsky Award Winners At The Monaco Dances Forum in Monaco on December 16, 2000.
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It just may be a subtle sign of acknowledgement of the relationship on Casiraghi’s part. Sources confirm to PEOPLE that Monaco’s untitled princess and the 35-year old Paris and Los Angeles-based film producer (his credits include Netflix’s The Little Prince) have quietly been seeing one another since December. They were introduced by friends over dinner and have since spent time in Paris and the new country residence Casiraghi moved to last fall following time spent in Rome with former boyfriend, Italian filmmaker Lamberto Sanfelice.

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French magazine Voici reports that the granddaughter of Grace Kelly and the son of Bouquet (a former Bond girl)share similar backgrounds. Both are graduates of the Sorbonne University in Paris, and each have children from previous relationships: Charlotte has a 3-year old son, Raphael, with comedian Gad Elmaleh, and Dimitri has a 6-year-old daughter from his marriage to model Masha Novoselova.

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And Casiraghi isn’t the only one of Princess Grace’s granddaughters with a new love in her life. Across the ocean, her cousin, Jazmin Grace Grimaldi, the 25-year old daughter of Prince Albert, has been seen with another celebrated name. Last week, she was spotted in Los Angeles with Ian Mellencamp, a 34-year musician and model who is the nephew of John Mellencamp. The duo were also photographed together in December at a book launch party in Miami Beach and at the 75th Anniversary USO Armed Forces Gala in N.Y.C.