Milan Spodniak and Ewelina Sroczyk briefly stopped their amorous encounter as the man strolled along a public footpath.
He took avoiding action to avoid an awkward confrontation, but when he glanced back the couple had continued their love making.
The dog walker decided to report the matter to the police and father-of-three Spodniak from Slovakia and Polish-born Sroczyk ended up being charged with public indecency.
And a sheriff has decided the dog worker should be compensated with £100 for witnessing the public sex session.
The court heard how father-of-three Spodniak, 41, who lives with his long term partner, and 37-year-old Sroczyk drove seven miles from their homes in Duns on September 21, 2020, to meet up at Greenlawdean Farm near Greenlaw which is a popular spot for walkers.
Joanna Waller, prosecuting, said:"At around 6p.m. the witness was walking his dog and saw the accused having sexual intercourse against a log pile in full view of the pathway.
"The witness changed his direction to avoid walking past the accused.
"The couple briefly stopped what they were doing.
"But as the witness walked away the accused continued to have sexual intercourse.
"On returning home the witness contacted the police."
The dog walker and another person then walked up the roadway where they saw the couple's vehicles parked and took photos of their registration plates which were passed to the police.
Sawmill worker Spodniak's lawyer Ed Hulme said his client made full admissions to the police.
He explained: “He went for a walk with the co-accused. There was no one else around and they did what they did. But they were seen.”
Mr Hulme urged the sheriff not to make his client subject to the notification requirements of the Sexual Offences Act saying it was not necessary.
Scroczyk did not attend court but submitted a letter in which she admitted her guilt.
The couple both pleaded guilty to committing an offence of public indecency by having sexual intercourse in a public place.
Sheriff Peter Paterson fined the pair £200 each and also ordered them to pay £50 each compensation to the dog walker. They were also told to each pay a £10 victim surcharge.