The Prince and Princess of Wales stunned passengers by jumping on the Tube to head to the pub where they enjoyed a lunchtime pint.
The royal couple caught the Elizabeth Line for the first time at Acton today and went three stops to Tottenham Court Road to attend the engagement in Soho.
On arriving at Acton station, the couple tapped in at the ticket barriers with Oyster cards before making their way down to the platform - and while on the London Underground, they met with Transport For London workers to hear about how they're preparing for a busy weekend.
At one point Kate was asked about Charles' coronation on Saturday and replied: "Yes, it’s going to be a busy time. We’re getting there. I still feel like we’re trying to get ducks in a row."
Kensington Palace also invited tube and train enthusiast, Francis Bourgeois, whose real name is Luke, to ride on the train with William and Kate as an observer. He has more than a million followers on Instagram, and royal aides said it was hoped he might bring the experience to a “younger audience”.
They alighted the Elizabeth Line, named after William's late grandmother, at Tottenham Court Road, where they walked past shocked passengers and took the escalator to the station's new Dean Street exit.
However, Kate, dressed in a recycled Eponine London red coat, appeared to commit a faux pas by standing on the left of the escalator, when guidance says passengers should stand on the right.
Leaving the station, they then completed the short walk to the Dog and Duck pub, where they were seen enjoying pints of cider as well as meeting members of staff from other businesses in the area preparing for the Coronation weekend.
Chatting, Kate revealed Prince George, Princess Charlotte, and Prince Louis were deeply immersed in the preparations. "The children are having their Coronation celebration at school today," she said.
The Princess explained that George was a page of honour during the service at Westminster Abbey and, asked if he was excited, she replied: "He is actually. Having done a few rehearsals, I think everyone is a bit more relaxed."
William, 40, was soon getting into the spirit of things after joining Kate in asking for a pint of his favourite tipple, cider. They were tempted by vodka but looted for something safer and were both handed pints of Mortimer's Orchard Cider.
"I find you get the best conversations in pubs," William said. "People are more relaxed. Restaurants you don’t get it. You get it with the food but not the conversation."
At one point he appeared to be talking about going out for a night out with former England footballer Wayne Rooney but he soon realised he was in danger of relaxing too much with the media in tow and said he would have to remember to keep his work head on.
"A couple of vodkas and we'll be all right," he joked.
They were then accompanied by pub managers Chris Watts and Maria Sojkova behind the bar, where William poured a "perfect pint", according to waitress Bernie Kidson.
It was the first pint of Kingmaker, a pale ale brewed to celebrate the coronation, ever poured.
Afterwards, they spent time meeting the hundreds of members of the public, who gathered outside the pub and posed for selfies with wellwishers.
People in the crowd travelled from as far as Australia, China, Canada and Texas to meet the royals ahead of the coronation on Saturday.
The princess was handed bunches of flowers, as was William, with one woman from Philadelphia saying: "I brought these for Kate but you can have them."
Talking with local businessmen as he sipped a pint in the pub, William said: "You always have the best conversations in pubs – you never know who you are going to meet."
He also joked that he would have to watch how much he drank and "get back into work mode".
Kate meanwhile said their eldest child George was "excited" about the upcoming Coronation and had been taking part in rehearsals.
She said the atmosphere in the area was "wonderful" and that excitement for the coronation was "already starting to build".
The couple's trip to the pub comes ahead of a busy few days for the royals with the Coronation of King Charles now just two days away.
Yesterday, they were spotted at Westminster Abbey with their three children Prince George, Princess Charlotte and Prince Louis to take part in a rehearsal for the big day.
They joined King Charles, Queen Camila and Princess Anne for the run through of Saturday's historical event.
The whole family looked relaxed and happy as they arrived, chatting to members of the church at the front door before heading inside.
George dressed in a smart blue suit while Charlotte, who celebrated her eighth birthday on Monday, wore a blue dress and cardigan. Camilla arrived in a car with two of her grandchildren, who will have starring roles at pages in the Coronation.
The rehearsal will have been especially important for George, who has been handed a key role in Saturday's event.
The nine-year-old future king has been made one of the Pages, and will walk behind his grandad to carry his robes as he enters and leaves Westminster Abbey.
Meanwhile, William will kneel before his father and vow to be his "liege man of life and limb" in the only homage of royal blood of the ceremony. He will also help clothe the King in his golden robe royal, also known as the mantle, ahead of his crowning.
