The fan, one of thousands who have come down to London for Friday night’s Euro 2020 Championship game against England, started doing the worm on a busy commuter carriage when his kilt rode up revealing all while his friends cheered him on.
Fans had been warned not to travel without a ticket for the match amid coronavirus concerns. Some 2,500 Scotland supporters will be inside Wembley for the Battle of Britain clash, with the crowd capped at 22,500.
But it appears that more fans have journeyed down to London without a ticket.
And they have been making the most of their trip. Social media has been flooded with footage of supporters dancing and singing their adopted anthem, Yes Sir, I Can Boogie, a 1977 hit by Baccara, outside King’s Cross and partying in Leicester Square and Hyde Park.
The much-anticipated match, the 115th in international football's oldest rivalry, is the first time the two sides have met in a major tournament since Euro 96, when Paul Gascoigne's famous goal sealed a 2-0 win.
Scotland fan Rab Foulis said supporters were "bringing a party atmosphere" to the city and "helping London's economy".
Speaking near Kings Cross, Mr Foulis said he had been waiting 23 years since wanting to go to the 1998 World Cup in France, where Scotland played their last major tournament but his wife did not let him.
Ecstatic that his new wife has allowed him to go to the Euros, he said: "We waited 23 years.
"Everybody's throwing a party atmosphere. We've all had double vaccinations and we're saying, you know what, why is Britain as a country still holding the economy back?
"So we're here and we're helping London's economy."
Another fan Mark Graham said: "It's a pity but it looks like Scotland will make their own fan zones.
"We've booked a pub for last night and a pub for tonight so we're well prepared."
Fans are predicted to buy 3.4 million pints during the game, while a total of 14.8 million will be sold across England and Scotland on match day, according to estimates by the British Beer and Pub Association (BBPA).
This comes as the Met Police's football chief has warned fans not to travel to Wembley without a ticket. Police have issued up a 48-hour dispersal order for in central London in anticipation of “anti-social behaviour”.
Chief Inspector Joseph Stokoe said: "It's a shame, it feels like there aren't enough places for the fans to enjoy themselves, but that's why the message has always been - if you don't have a ticket, don't travel.
"Enjoy the match, enjoy the event locally, in a safer event... don't come here, because unfortunately because of what's gone on across the world, we've been unable to provide the amount of fan zones you might expect in normal times."
He said officers have been reminding fans that some Londoners are "still living under the fear of the pandemic", adding that spreading the Met's resources between fighting crime and policing the football is "a balancing act".
Scotland's First Minister Nicola Sturgeon has echoed the warning for Scottish fans to stay away from London, adding that coronavirus is not a fan of Scotland or England's men's football team.
She said: "I know these precautions are tiresome for everybody in every context and they're particularly tiresome when people are trying to enjoy the normal pleasures of a football match.
"But this virus, it doesn't care about football - it's not a Scotland fan or an England fan, it only cares about spreading from one person to another."