A Derbyshire pensioner has been found guilty of voyeurism in men's toilets in Derby city centre.
A trial was told how Geoffrey Beighton was spotted by one security guard in the Eagle Market adjacent to Intu Derby shopping centre "waving his foot" under a locked cubicle door - a move that the court was told was a "sign" that he wanted to engage in sexual activity.
A second security guard said minutes later he walked in to the public toilets and saw the 70-year-old standing on a toilet bowl, peering over and smiling at whoever was in the one next door.
Beighton, a father and grandfather, told his trial he was a former steel metal worker and mistook the man in the cubicle as a former colleague who had once played a joke in him and who he wanted to return the prank on.
He said he was "not there for any sexual gratification and had no sexual interest in men at all".
But magistrates found him guilty of one charge of voyeurism.
Fiona Cannon, chair of the bench, said: "You have been found guilty of this offence of voyeurism and an aggravating fact is that it happened in a public place.
"We heard evidence that you started watching your victim over the top of the cubicle for longer than was necessary and we believe that was obviously for some kind of sexual gratification."
The victim, whose identity is protected by law, told the hearing that he did not see Beighton, of Newton Lane, Newton Solney, watching him as he was playing with his mobile phone.
But when he came out of the cubicle and was told by a security guard what happened he wanted to make a police statement and told the hearing he felt what Beighton had dome made him feel "dirty".
Security guard Richard Barrett said the offence took place shortly after noon on September 30.
As he walked into the public toilets he saw Beighton come out of the far cubicle and walk up and down.
Mre Barrett said: "We had reports of issues in the toilets of goings-on between males so had upped our checks to every 30 minutes to make sure nothing untoward was happening.
"I saw this man place his foot under the door of one of the cubicles and start waving it from side to side.
"I had been told this was a sign for wanting to engage in sexual activity."
Mr Barrett said he informed a colleague, Graham Muggleton, who then went into the public toilets and saw Beighton looking over into a locked cubicle.
He said he asked him what he was doing and Beighton replied "I thought I knew him."
Beighton was arrested and questioned about the incident and told officers he thought the man in the cubicle is someone he once worked on a building site with and had thrown water over him a number of years ago.
Giving evidence at his trail at Southern Derbyshire Magistrates he said: "I thought here's a chance to get my own back.
"I feel quite embarrassed about it, it was quite a silly thing to do.
"I can see what people think but I have no sexual interest in men."
Magistrates fined Beighton £165, ordered him to pay £50 to his victim and £100 costs.
