A man, his boyfriend and a third man had an orgy on a late-night London subway train in front of other passengers.

Nicholas Mullan, 24, and George Mason, 35, engaged in an array of sex activities which they filmed on the Northern Line between Leicester Square and Waterloo stations.

Prosecutors say another man was involved in the astonishing incident which also involved extensive sexual activity. The whole affair happened on Feb. 19, 2018.

The two men appeared in court on Friday and pleaded guilty to one count of outraging public decency.

Outlining the case, prosecutor Victoria Murphy said: “This is a case of outraging public decency on a London Underground train.

“On the 19th of February 2018, British Transport Police were contacted to a report of a video which had been posted online showing three men engaged in explicit sexual acts on a train.

“It showed full sex, oral sex and masturbation in the presence of the traveling members of the public.

“It appears to take place on the Northern Line between Leicester Square and London Waterloo.

“It was reported by a man who was also gay who thought the video overstepped the mark and was morally unacceptable.”

She added a British Transport Police investigation later identified two of the three men – the third is thought to have escaped identification because their face was pixilated.

The two men will appear in court on Feb. 1 for sentencing.