A man who flashed his genitals while at a bus stop claimed he was "adjusting his trousers", a court has heard.

Kevin William Pope (66) was walking in High St in Mosgiel, Dunedin when he pulled down his pants and committed the obscene exposure.

A member of the public called police and the defendant was found nearby.

Pope admitted being at the bus stop and initially explained he "went for a wee".

He denied intentionally performing the lewd act.

Defence counsel Jo Turner said her client had been doing some window cleaning in Mosgiel when the incident took place.

"He stopped at the bus stop and adjusted his trousers. He did so and the offending happened," she said.

"He is really sorry for any offence. It wasn't his intention to do that."

Turner accepted Pope had an extensive list of convictions but highlighted the fact his last was five years ago.

Judge Thomas Ingram noted that was for offensive behaviour.

"You've been doing it all your life," the judge said, leafing through a list of convictions going back to the 1980s.

"Your record's not exactly flash."

He said Pope was a little too old to be placed on community work.

He was fined $250 with court costs $130.

Turner said the defendant would pay the fine off in instalments.