Huan was also prince to Boyle's Aurora in the company's Sleeping Beauty in 2011.
"He said to me then, 'Let's just dance for us.' And it was like that, in the pas de deux, just him and me."
Boyle looks dreamy at the memory. "When I looked at him, it seemed as if we were the only two in the whole universe. Qi is so my prince. He calms me down. He is lovely."
But Boyle has to share him and the Odette/Odile role this season, with principal guest artist Gillian Murphy, who leads the A cast. Another guest couple, Amber Scott and Ty King-Wall, from the Australian Ballet, will also dance the lead roles in the Auckland leg of the tour.
Murphy and Huan have developed a special partnership in previous RNZB productions, in Giselle and 28 Variations on a Theme by Paganini, and it is a compliment to Huan that Murphy, with a stellar international career, also rates him as a "wonderful" partner. They agree that a history of dancing together adds an extra layer to a partnership. "You get to know what the other person wants," says Huan. "You don't have to say so much, and you don't make so many mistakes."
"A dance partnership is a lot like a marriage," adds Murphy, "It is so much about communication - and diplomacy."
"The role is different with different partners," says Huan.
And on producing all that princely romance and passion?
"You use your imagination," he says, "and make her into the one you love!"
"We are both engaged - to other people," laughs Murphy, whose fiance is artistic director Ethan Steiffel. "I asked Ethan what he thinks makes a good ballet partnership and he said instinct and strength."
Musicality, co-ordination, chemistry, connecting with the other person - and not always doing exactly what you did before, are all important factors to Murphy. Being spontaneous and playing off each other makes a partnership more fulfilling, she says.
"The dialogue has to be about your body, your energy, the character. This ballet is about the power of love. It is meaningless without that deep connection."
Murphy also partners guest artist Karel Cruz, from Pacific Northwest Ballet. Cruz's original partner for the season, Carla Korbes, was injured and unable to travel. Cruz and Murphy had barely two days to practise before opening night in Wellington in mid-July. Their performance was fabulous, but if Boyle is looking for a tall partner, Cruz would fit the bill magnificently, at 1.93cm.
"I have danced with many tall men," says Murphy, "but Karel is the tallest. Height does change things - just looking up at him is very different."
She describes the soaring lifts with Cruz as "wild".
His height gives Cruz a very princely bearing on stage, and he has great dramatic skills, portraying a very caring and passionate Seigfried. Physically his height makes partnering "both easier and harder," he says.
While "overheads" - reaching up to support his partners' extended arms while she pirouettes - is easier, he also has to bend lower to pick a partner up.
"It is a long way down - and a long way up," he says, and confesses to some lower back issues as a result. But there are worse things, and even "terrible things that happen on stage," he says.
In one performance, on tour from Venezuela and dancing in Washington DC as the prince in The Firebird, he wore a beautiful braided jacket, while the Firebird sported a very close fitting and therefore very elastic unitard.
"We parted, after a very intense pas de deux," he says. "But her unitard was hooked on my jacket - and we bounced back and forward a couple of times" - he waves his arms some distance apart - "before we got free."
For young dancer Kohei Iwamoto, partnering another of the company's rising stars, Lucy Green, the role of Siegfried is challenging.
"Lucy is a superstar," he announces. "We did Giselle and Bierhalle together. She is really strong and a good height for me. She is very smart - she even understands my English - and she helps me a lot. She has good jumps and stamina, which is important. And her turns are very good. She is like Gillian Murphy - she turns herself a lot so I don't need to do it. That is really helpful for boys."
Green says the two most important elements in a good partnership for her are trust and chemistry.
"When it comes to a performance and you feel the pressure to perform well and those nerves start to fire up, it's important to know you can trust your partner and feel confident and comfortable with him - or those nerves can get the better of you.
"As for the chemistry - if the audience doesn't feel that the love or desire or whatever you are attempting to convey is genuine then we aren't really successfully telling the story and becoming our characters ... there are some huge technical challenges that can be quite nerve wracking, but if you focus on the character you find the technique less daunting."
Iwamoto's first stage lift was in Cinderella last year, he says, when he danced with Tonia Looker, "a very small, light girl".
"I don't like partnering much," he confesses. "I get really stressed. You have partnering classes in ballet school, but not so much as other things. You can go to the gym to get strong. But on stage you just have to do it. You can stop pressing in the gym, but not in a show.
"In partnering the audience is mostly watching the girl, not me. But a principal dancer has got to have good partnering. A good pas de deux makes a good show."
There is a spectacular fish dive in one of Swan Lake's pas de deux. It is almost inevitable that the prince's face gets brushed by the underside of Odile's tutu on the way down.
"Always!" says Iwamoto. "Very scratchy! I think I feel blood! But then, I wonder how it feels for the girl being caught around the ribs. I think I am happy to be the boy."
Performance
What: Swan Lake with the Royal New Zealand Ballet
Where and when: Bruce Mason Centre,
Takapuna, August 17-18; The Civic, August 21-25
