The couple’s mutual friends had implored them to meet time and again. “Lyor says that everyone kept shooting Cupid’s arrows, and we kept dodging them,” says Xin. But it was not until a Christmas vacation in St. Barth’s that they finally met. “Wendi was the one,” Xin says, referring to her dear friend Wendi Murdoch’s matchmaking. “When Wendi decides something, she makes it happen.” Murdoch knew that Lyor, the global head of music for YouTube and a principal shareholder at 300 Entertainment, would be staying at the hotel next door, but the actual coup de foudre was serendipitous: Xin and Lyor bumped into each other on the beach.

Lyor’s proposal came on the heels of another friend’s wedding in Florence. He planned to ask Xin at the Basilica of Santa Croce, where there is a favorite statue of Dante, but was waylaid by Xin’s insistence that they visit the Uffizi instead. Lyor got down on one knee in the Piazza della Signoria. “I think he saw the replica of the David and got inspired,” Xin remembers. “It was the morning after the wedding, so we were both in a daze.” Moments later, they extended their trip and caught a train to the Villa Treville in Positano.

The initial idea was to marry in Paris the weekend after Art Basel. Xin, who was born in the Jilin province, had relocated to the French capital at age 20 to pursue modeling after an early career as a professional basketball player. It would have been a fitting location to start the next chapter of her life with Lyor. But, as she puts it: “I was too busy!”

“Lyor kept saying, ‘If you want to get married in Paris, we have to start planning today.’ I said, ‘Don’t worry, I’ve already found the dress.’” Actually, it was two dresses: During Frieze week, in October 2015, Xin visited Alexander McQueen’s Sarah Burton in London to decide on a dress. The following March there came a second wedding dress for dinner and dancing, this time from Gucci’s Alessandro Michele. It went down the runway in black, but Xin ordered it in gold to please her Chinese friends and family, for whom the color signifies good luck. Ultimately, for the sake of logistics, it was decided they would marry at Lyor’s Leroy Street Studio–designed house in Sag Harbor.

With the help of Nadine Johnson, they employed event planner Olivier Cheng to coordinate the wedding, confident that he would deftly negotiate the expectations of both the New York–based and out-of-town guests. Xin’s famous unflappability triumphed in the days leading up to her wedding: She had rented a dozen houses in Sag Harbor for Chinese friends and family, and arranged hair, makeup, and transportation for all of them. For her own look, Xin opted to go low-key, employing help from Tracy Alfajora and Bumble and Bumble’s Jordan M. “After years of modeling, I could never want to sit in the chair for two hours,” Xin says.

The ceremony itself was a seamless coupling of Jewish and Chinese traditions. Xin’s feng shui master (“It’s better if we don’t name him,” she demurs) insisted that she and Lyor be married before 7:00 p.m., based on their times of birth; for the Americans, this simply meant a perfect sunset vista across the water. Well in advance, Xin had asked Wendi’s and Lyor’s daughters to be her flower girls (they all chose pink-hued options by Peter Copping for Oscar de la Renta), but hadn’t ever considered having a maid of honor. “I had no idea I needed one!” Xin says. Her sister Xi, a director at Gagosian in Beijing, accepted the challenge last-minute, standing opposite Az, Lyor’s son and best man, in a midnight blue Gucci. Xin walked down the aisle to “Charlene” by Anthony Hamilton (who performed after dinner) and the couple was married by Rabbi Peter Rubinstein under a chuppah of white garden roses. Hugo Ou, a Chinese friend, gladly translated the essential bits of the Hebrew and English, with a much-appreciated emphasis on when to yell L’chaim!

With rings exchanged and glass broken minutes before the feng shui master’s deadline, caviar carts were rolled out and Xin changed from her strapless and Watteau-pleated McQueen of embroidered silk into the dazzling gold Gucci. (Xin also exchanged one pair of Christian Louboutins for another.) The tented dinner coincided with speeches by friends and family—Xin’s father was equally touching in translation)—followed by a surprise wedding gift from Murdoch after the first course had been cleared. She had commissioned the artist Cai Guo-Qiang to orchestrate a fireworks show that was anything but the standard wedding fare: Cai lit up the bay in jewel-toned starbursts, columns of rockets sent up in musical syncopation, and a fan of what appeared to be glittering gold dust. All this was succeeded by a finale that featured a canon’s worth of 500 firecrackers that landed in the water only to return, several seconds later, floating like lily pads on fire.

Before the pyrotechnics began, a 30-minute deluge threatened to allay Cai’s meticulous preparations. But, as if planned according to the feng shui master’s schedule, the sky cleared just in time for the show, revealing a full moon. “After that, Lyor said, ‘Your master was right. We’ll call him for everything.’ ” Which is a useful idea for a couple with itineraries as busy as Xin’s and Lyor’s. Timing, indeed, is everything.