Disgusted Simon Cummins said he and his friends were stunned as they heard the woman’s sexual moans while walking along the walkway on the beach.
The 31-year-old had been to a friend’s stag party the night before but was up at 9am to pick up his car to travel to a charity football match, which is when he saw the display.
However, as the party passed the famous Brighton Pier, they say they first heard and then saw a blonde woman gyrating on top of a man on the beach.
Just yards from the sordid scene holidaymakers and children can be seen passing by.
At one point a youngster points to the lewd goings on before his disgusted mother pulls him away.
The incident happened close to the pier on the public side of Brighton beach. It is near the more secluded nudist beach which is situated on the other side of the pier.
According to Cummins, at one point several men approached the couple and one attempted to join in.
Sussex Police said they did catch up with the couple and made two arrests before issuing on-the-spot fines.
“It was broad daylight, the nearest families were 10 metres away if that, there were kids playing nearby. It was disgusting,” the Daily Mail quoted Cummins as saying.
“I have young nephews and nieces and if I had seen that kind of thing going on in front of them I would have had a word.
“The woman and the man didn’t look like they were druggies, or dishevelled, they looked like normal everyday people, except it looked like they were [having sex] on a beach in the middle of the day.
“It was like an orgy or the last days of Rome, it was a horrible sight to see. At one point a little boy pointed over at the couple and his mum had to haul him off in disgust.
“It’s not Ibiza at 3am in the morning, this was in broad daylight with families around and they just didn’t seem to care,” he said.
Cummins, who was with his friends Ben Stone and Richard Jones, said the reason they noticed the couple copulating was because they heard the woman’s ‘screams’.
“Ben said ‘what’s that noise?’. We thought there was someone in trouble but when we saw what was going on we realised she wasn’t screaming for help,” he said.
“As it went on things got even worse when a few blokes seem to turn up. It was disgraceful.
“When the police finally turned up I was shocked because it seemed to me they were almost scared about approaching the couple, and then they just gave them a fine. They should have been locked up,” he added.