One outraged father took a photograph of John Baird's bare bottom as he "simulated sex" by thrusting it backwards and forwards, with the image being shown in court yesterday.
Prosecutor Andrew Richardson revealed that Baird, 35, had been seen drunk at around 3pm on the day of the offence and, two hours later, a man driving with his daughter saw the accused at the bus stop on the other side of the road.
Mr Richardson then produced a photograph of the scene, commenting: "A picture tells a thousand words.
"It shows the accused with his trousers round his ankles and his bare bottom.
"Other members of the public driving along also saw the accused.
"He was seen what they all thought to be having sex with someone at the bus stop."
He added: "They couldn't see the other person involved, but they could see the accused's exposed bottom making thrusting motions."
READ: TEACHER FINDS CHILDREN, 5, SIMULATING SEX IN THE SCHOOL BATHROOM
According to the prosecution, several people, including a member of staff at the school club in Falkirk, Scotland, shouted at the accused and the person he was with to stop because there were children nearby. But the couple paid no attention and carried on.
When Baird was later apprehended by police, he told them the whole thing was "a joke".
Glenn Fraser, defending, said: "It was certainly vulgar, but it was a simulated act and he was wearing a thong."
Baird pleaded guilty to committing an act of public indecency by engaging in a sexual act in a public place. He will be sentenced later today.