Lucky Blue: Mormon model, 17, on chicken feet, his beautiful family, and his Chinese fans

Lucky Blue, who is not a racehorse, as his name might suggest, but rather a 1.9-metre, 17-year-old model, is learning how to dance. Basic moves. The grapevine. A decent step-touch.

"Just remember when you're step-touching to lead with this." Here, Danny, the male dance instructor leading this private lesson at a small Los Angeles studio, pats the side of Lucky's butt. This makes Lucky blush. He buries his hands in the pockets of his skintight black jeans.

Today's lesson is worst-case-scenario prep for Lucky's upcoming appearance on The Ellen DeGeneres Show the following week, in case the talk show host requests a short boogie from her guest, as she often does. Lucky can't seem to find the rhythm. His step-touch has a jitteriness that makes it look like he's tiptoeing around dog poop. "I suck at this!" he shouts good-naturedly.

Danny tries another tack: "Take your hands out of your pockets! Use your lanky arms - let them swoop you this way and that." Lucky starts swinging his arms, his face scrunched in painful concentration. He looks like a very thin monkey. Or any other 17-year-old boy forced by social circumstance to dance.

Lucky is just a kid, after all, which can be hard to square with his smouldering gaze in the new Tom Ford campaign or his Nordic-vampire visage in the Annie Leibovitz-directed Moncler shoot. Signed at age 12, he's already walked in more than two dozen shows this year, including ones for Balmain and Sacai at Paris Fashion Week. On the runway, he commands a Bond-villain-esque presence. Lucky is fairly well known in the United States - for a male model, at least - but he's extremely, and somewhat inexplicably (even the South China Morning Post's fashion editor admits to being bamboozled), famous in China, where they call him Xiao Xian Rou ("Little Fresh Meat"), a common nickname for young good-looking men. In April, he graced the front page of mainland lifestyle magazine Modern Weekly, the next month he dominated a joint cover shoot with one of his sisters for Harper's Bazaar China; the issue was headlined "Lucky Blue, 16: handsome rebel". He has 350,000 followers on Weibo and more than a million on Instagram.

"Walking is pretty easy," he explains as we leave the studio together. "You just have to be confident, like not caring. And honestly, people think about their walk too much, so they try to do something really interesting, but the designers hate it."