But the 26-year-old model made sure to get the official go-ahead from the bride first.
Delevingne turned heads as she strolled into St. George’s Chapel at Windsor Castle wearing an Emporio Armani tuxedo featuring a cropped jacket, cummerbund, cigarette pants, black pointy-toe pumps and a show-stopping top hat.
“Eugenie has been a friend of mine since I was a kid, and I’ve always wanted to wear tails,” she told Grazia magazine, per Marie Claire. “I texted her, as I wasn’t sure about it, and she was like, ‘Of course, I expected nothing else from you!’ “
Delevingne added, “I found it interesting how many people came up to me and said, ‘You’re so brave to wear that!’ I was like, really? I feel way more comfortable like this.”
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The 92-year-old monarch, who never wears slacks, prefers women in the royal family to wear dresses or skirts — something which Meghan has broke tradition on.
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A source previously told PEOPLE that although Meghan has quickly adapted to many of the minutiae of royal dos and don’ts, she “has found certain rules in the royal household difficult to understand, like the fact that the Queen prefers women in dresses or skirts rather than trouser suits, and is often asking Harry why things have to be done in a certain way.”
“I think she finds it a little frustrating at times, but this is her new life, and she has to deal with it,” the source added.
So while Delevingne’s look might not have the Queen’s stamp of approval, the Internet certainly fell in love with her style statement.
Delevingne was joined by her friend, journalist Derek Blasberg, and her family, including sister Poppy Delevingne and her husband James Cook.