"I've named the dress Bertha, like Big Bertha," chuckles Annalene Beechey, who plays widowed teacher Anna in the show. "The fabric is weighted down at the hem so it lifts and dips perfectly to move with me, but I always say there's three of us in the Shall We Dance number - me, Jose and Bertha."
Even Jose Llana, who plays the King opposite her and was also the lead on Broadway says there are "gasps from the audience" when Anna appears on stage in the dress.
"The King and I means a lot to a lot of people," added Beechey, who went to Wychon Croft School in Coventry and played the role of Anna in the West End. "It's very much a family show that is rich to the ear and the eye.
"I remember watching it with my mum and I meet people at the stage door now who often say it was their grandmother's favourite. We look down at the audience and see three generations together. There's often children coming to see it who are only six years old and they are mesmerised."
For those of you unaware of the story, the King and I is set in 1860's Sian, now known as Thailand. Newly widowed Anna Leonowens arrives from England with her son Louis to be the schoolteacher for the children of the King of Siam.
Although the King wants to modernise his country through Western education, the two clash over differing traditions and at first struggle to find common ground. Ultimately, Anna and the King teach each other about understanding, respect, and love that can transcend the greatest of differences.
"I wanted to bring back something of the political aspects that had been written out of the show. He is a political leader who invites in a foreigner. If that's a lesson we can learn in these times. A lesson about looking past your differences.
"The story is driven by the love of their children. Anna is there to teach the King's child and to support her own. There's a lot of children on stage and it's hard not to smile around them. It's a joy to come to work."
"You see a show somewhere and it sparks something in you and you think that's what I want to do," explained Beechey. "It's a passion you need to fulful. I did amateur dramatics as a child but when I saw Phantom of the Opera in the West End, that was when I knew I wanted to do this (as a career)."
Llana nods and added: "I grew up in a suburb in Washington DC and saw every Broadway show going through it, shows like Cats and Les Mis, which propelled me to take more voice classes. This King and I will be the same for some children in Birmingham seeing this now."
Acclaim for the production led to Beechey and Llana performing the Shall We Dance scene at this year's Olivier Awards in the Royal Albert Hall. Something that Llana reveals was a moment he'll remember til the day he dies as it was such an iconic venue for him.
"If we have done our job well as actors, the audience is waiting for us to do the Polka together," added Beechey. "They will have laughed with us and by the time we get to Shall We Dance, there is often an audible gasp as he pulls Anna up close to him to do the dance. That's the moment you know you've done your job right."
Tickets start from £17. Find out more about the show and get your tickets here.
The King and I is 2 hours 55 minutes including an interval.
Watch a preview of the King and I UK tour here: