A porn actor who filmed himself having a threesome on the London Underground in front of passengers has been fined £1,000.

George Mason, 35, had sex with his former partner Nicholas Mullan, 24, and an unidentified third man on a Northern line Tube train between Leicester Square and Waterloo.

Mason posted the footage on Twitter months later using the “Hung Young Brit” account, with captions reading ”Full-on live sex in front of the general public on Tube” and ”100 per cent genuine footage”,

It was reported to police by another user who thought it “crossed the line of what was acceptable behaviour”, Westminster Magistrates’ Court heard on Friday.

Both men were subjected to a “virulent and quite disgusting campaign of hate” on social media after details of the incident emerged, according to their lawyer Howard Cohen.

Underground art: The colourful past of the Tube Show all 11 1 /11 Underground art: The colourful past of the Tube Underground art: The colourful past of the Tube Please avoid the rush hours by Victor Galbraith, 1959 Underground art: The colourful past of the Tube Primrose Hill by Paul Catherall, 2007 Underground art: The colourful past of the Tube Power by Edward McKnight Kauffer, 1930 Underground art: The colourful past of the Tube Lord Mayor’s Show by Edward Wadsworth, 1936 Underground art: The colourful past of the Tube Guildford by Dorothy Paton, 1925 Underground art: The colourful past of the Tube London Transport by James Fitton, 1948 Underground art: The colourful past of the Tube Eastcote by Charles Pears, 1913 Underground art: The colourful past of the Tube Cup Final by Tom Eckersley and Eric Lombers, 1938 Underground art: The colourful past of the Tube Brightest London is best reached by Tube by Horace Taylor, 1924 Underground art: The colourful past of the Tube Boat Race by Tom Eckersley, 1951 Underground art: The colourful past of the Tube The Seen by James Fitton, 1948

Mason, of John Ruskin Street, Southwark, south-east London, and Mullan, of Castlehume Gardens, Belfast, both admitted outraging public decency.

Chair Lucinda Lubbock, who viewed the footage before announcing the sentence, said: “This was a very unpleasant and serious offence on the public Underground system.

“The way it took place, the seriousness of the offence, is exacerbated by the fact that it went on social media.”

In addition to the £1,000 fine, Mason was also handed an 18-month community order and told to pay £170 in costs. Mullan, who is on benefits, was not fined but told to pay £170 costs and carry out a 12-month community order.

Ms Lubbock added: “We feel that this is a lesson to both of you. As your defence lawyer said, you have been humiliated in the court of social media.”

Prosecutor Robert Simpson said the footage was recorded in July 2017 but was not posted on Twitter until February last year.

Support free-thinking journalism and attend Independent events

He said: “The two men in the dock engaged in various sexual acts on a Tube train, including full anal and oral sex and masturbation, and this was in the presence of the travelling public.

“The incident is recorded by them and the video of what happened was subsequently uploaded on to Twitter, where another gay man saw it, thought that had crossed the line of what was acceptable behaviour and the incident was reported to the police.”

Mullan was traced through another clip on the Twitter account which linked to an escort website containing his mobile number under the name Toby. He was identified by distinctive arm tattoos seen on the video.

Mr Cohen said that the pair had recorded the video as they travelled back to Mason’s flat after a day out.

“During the course of the journey, the idea came about that they would have sexual relations on the train,” he told the court.

Mason “works in the adult film industry” and provided the footage to the Hung Young Brit website, the lawyer added.

He was then “required to upload a snippet of the material on a Twitter account” and used the “salacious” title to attract attention, Mr Cohen said.

Simon Arloff, from the Crown Prosecution Service, said in a statement: “This was an outrageous and distasteful act within sight of passengers who were travelling on public transport.

“Mason and Mullan thought they were being sexually risky and could earn some money from their stunt, but in doing so they showed complete disregard for other passengers on that Northern line train.”