When we see them in public it's all smart suits, designer dresses, polite conversation and warm but controlled smiles.
Now Kate and William have given an unprecedented glimpse into their surprisingly normal life behind closed doors in a very candid radio interview.
The pair dropped in on the Scott Mills show to surprise Radio 1 DJ Adele Roberts who is running the London Marathon on Sunday for their Heads Together Campaign and were surprisingly forthcoming when quizzed about their day-to-day life, said the Daily Mail.
They revealed they enjoy ordering their favourite takeaway curry while lounging in their comfortable clothes watching Homeland or Game of Thrones at Kensington Palace.
William divulged he and Kate had partied with Tinie Tempah at Radio 1's Big Weekend in Bangor and even joked about his notorious "dad dancing" in Verbier, when he admitted the couple would love to go to Glastonbury but haven't yet managed it.
"I've got into enough trouble with my dancing recently. So it's probably best to stay away from that one," he said.
Coldplay at Wembley was the last concert they attended, and William even admitted to texting song requests to DJs under a fake name in order to get shout outs on the radio.
"I got a shout out the other day from Adele, and one ages ago from Sara Cox," he said.
"I felt very privileged. I'm probably on the edge of your age limit, I'm probably supposed to go on radio 2 now but I'm hanging on in there."
"What were you doing texting while driving?" Kate asked, laughing.
William rushed to assure her, and listeners, that he pulls into a lay-by as it "would be illegal" otherwise.
On the subject of music, William said they had been to Radio 1's Big Weekend where he got "a very sweaty man hug from Tinie Tempah".
"Do you ever think, if I wore a comedy beard and hat I could go into that crowd?" Scott asked.
"It has crossed our mind - who's to say we haven't done that already?" William replied.
Of course, with two young children at home the couple don't have much opportunity to go to gigs and festivals and are more likely to be at home watching children's TV shows with George and Charlotte.
William admitted to getting slightly fed up with an endless barrage of cartoon characters, saying: "Our daughter gets really upset if you're not showing due dillegence to the characters."
Fireman Sam is the current big hit with the young royals, while George is past the Peppa Pig stage.
Once the children are in bed, the pair often like to relax with a box set, naming Homeland and Game of Thrones as their go-to shows, but laughed when they were asked if they ever watch Eastenders or Gogglebox.
"So do you ever order takeaways? What's your favourite?" Scott asked.
Kate, who looked stunning in black skinny jeans and a Temperley London top added: "Absolutely and curry - definitely!"
However, when Scott asked if the local takeaways thought someone was pulling their leg when someone placed an order for Kensington Palace, William explained: "It doesn't usually get ordered to the Palace to be honest, normally someone goes and picks it up."
Scott was eager to find out what the royals wear during the nights they stay in to relax and asked if they wear jogging bottoms.
William replied: "I've got my comfy clothes, yes. I don't know if they're the same as what you wear though."
Today, William's grandmother the Queen is celebrating her 91st birthday and the couple were asked what they had given Her Majesty as a gift.
Admitting that it's difficult to buy for the woman who has everything, Kate told William: "You're good at making things".
He continued: "The great granchildren can make things. It doesn't matter what it looks like, it always goes down well.
"George does arts and crafts. He's very good."
As Kate accused him of trying to take credit for his son's artwork to pass off as his own gift, William joked: 'This is putting the marriage on the line.'
The Duchess was also quizzed over her multiple monikers with Scott pointing out that she's known as Kate in the media, while William refers to her as Catherine.
He added: "I heard a podcast with Prince Harry where he said "William and Kath" and that really confused me. Is that just a thing in the family."
"I'm not sure. I'm not that familiar with it," she said. "I'll answer to most things though."
Scott wanted to know if the royals have a family WhatsApp group William could use to send his birthday to the Queen.
Although he avoided giving a direct answer, William replied: "I can do a shout out on Radio 1 instead."
He then used the opportunity to make a serious point about the mental health programme he, Kate and Harry have been promoting this week. He said while social media is a great way of staying in touch, it can never replace face-to-face conversations with friends.
Scott wanted to know if the royals have a family WhatsApp group William could use to send his birthday to the Queen.
Although he avoided giving a direct answer, William replied: "I can do a shout out on Radio 1 instead."
He then used the opportunity to make a serious point about the mental health programme he, Kate and Harry have been promoting this week. He said while social media is a great way of staying in touch, it can never replace face-to-face conversations with friends.