A "toxic relationship" between feuding neighbours had been simmering for 13 years when a woman damaged a van in a parking dispute, a court heard.
Jean Shanahan (55) bent the van's wing mirror when she became annoyed because it was parked outside her house.
She and her husband had fallen out with their neighbours, the Montgomerys, years earlier over building work carried out on one of their homes.
Dublin District Court heard gardai received regular "trivial" complaints from each side and both couples had set up CCTV cameras on their homes to "catch the other out".
Shanahan, of Alpine Heights, Clondalkin, pleaded guilty to damaging the van owned by her neighbour, James Montgomery.
Judge Ann Ryan adjourned the case, saying she would leave the accused without a conviction if she paid €245 compensation for the damage.
Shanahan, who has a hearing impairment, had the assistance of a sign interpreter for the court proceedings.
The incident happened at 4.40pm on June 5, 2014.
Mr Montgomery's van was outside on the road when "words were exchanged" and Shanahan pushed back the wing mirror, damaging it.
On the day, Mr Montgomery had parked the van outside and the majority of it was in front of the Shanahans' house.
"There have been a number of difficulties, and one of the difficulties was that Mr Montgomery had been parking the van in front of their house. He doesn't do that any more," said defence solicitor Alan Doyle.
Mr Doyle said Shanahan had been out sweeping the road and the van had driven over her sweeping brush.
"That got her excited," Mr Doyle said, adding that it was clear on CCTV footage that she was trying to remonstrate with Mr Montgomery and tried to open the door and "then slaps the wing mirror".
She was surprised by the damage that was caused. The prosecuting garda said he did not believe the brush was driven over "on that day".
Mr Doyle said his instructions were that it was that day.
"This is terribly unfortunate, it's very sad that it's come to this," he said.
Shanahan and her husband had been good friends with the Montgomerys until 13 years ago when there was a "falling out in the relationship which has been quite toxic ever since," said Mr Doyle.
The relationship had turned sour over building works that were done on one house.
Gardai had received complaints almost on a monthly basis from each set of neighbours about what the other set was doing.
"A lot of them would be quite trivial and petty," said Mr Doyle. "They both have CCTV set up on both their houses in order to catch each other out."
Judge Ryan said: "It's a terrible waste of anyone's life to be behaving like this. It's incredibly sad that grown-ups can behave in the manner described on both sides. It's just extraordinarily juvenile."
The judge added that if they did not stop, the rest of their lives would be just "tit for tat."
She adjourned the case and said she would apply the Probation Act if Shanahan paid for the damage.
The accused was excused from attending again.