A fight broke out at a swingers party when a man asked a woman to help him put a sock on.
David Tillyer thought his partner Evelyn Hodder was being propositioned by John Watson at Infusion in Blackpool.
But when the 47-year-old confronted Watson, 50, he was attacked and had to be taken to hospital for treatment, the reported.
Watson, from Blackpool, was found guilty of causing actual bodily harm after a trial at Preston Magistrates’ Court.
The court heard that Mr Tillyer and Ms Hodder were about to leave the New Year’s Eve party when the victim saw his partner helping Watson with his sock.
He then asked Watson: ‘What sort of man needs help putting a sock on?’
Watson pushed Tillyer backwards, punched him and headbutted him, the court was told.
Mr Tillyer said: ‘It was a really violent attack. This is a place we know and we feel comfortable in.’
The couple had travelled from their home in Nottingham for the event, prosecutor Kerry Grieve said.
Mr Tillyer told the court he was there to watch other couples have sex.
The fight was broken up by other people at the event and Mr Tillyer later went to hospital.
Watson said he had asked for help with his sock as he suffers from athritis, adding that he only pushed Mr Tillyer and did not punch him.
PC Steve Johnson told the court that police were not able to consult CCTV footage as cameras are not installed at the venue.
Watson will be sentenced at a later date.
Got a story for Metro?
If you have a story for our news team, email us at .
You can also follow us on and .