A couple writhe naked on the sand while the waves break gently behind them.
A jogger runs past and he does not bat an eyelid at the sex scene playing out yards away.
The “lovers” are in fact porn stars, and they are filming on a beach in Spain — fast becoming the adult movie capital of the world.
While passers-by in the UK would be shocked, producer Thierry Kemaco — renowned in the industry for his outdoor films — explains: “In Spain, the people watch and when you finish, they applaud.”
This liberal attitude may be less surprising to a younger generation brought up on a sex-rich diet of TV’s Love Island and online porn.
But there is still plenty to shock six young Brits who travelled to Spain to explore the booming sex industry for BBC3 documentary Porn Laid Bare.
Their journey takes them into the dark underbelly of the scene, where they hear tales of human trafficking, forced drug taking and violence.
They are also on set to witness the nerves of a young Russian girl when she realises she is expected to have sex with 20 men.
The Brit group, who were chosen for their varying attitudes towards porn, include freelance journalist Neelam Tailor, 24, porn star super fan Ryan Scarborough, 28, student Anna Adams, 23, and the youngest of the group Cameron Dale, 21.
Not one of them comes away unchanged by what they witness.
The film is directed by Rob Diesel, who also stars in it. He says he went to Spain from his native Sweden because “they’re more liberal here”.
The website he is making the film for had 7.6billion visits last year and turned over £6.9million.
Rob says: “It’s a multi-billion-pound industry in Spain.
“They respect you as an artist. It’s a job here, it’s not like, ‘Look at the freaky guy there who’s doing porn’.
“There’s so many myths in porn still. You don’t have to do anything you’re not comfortable with and the artists I work with all have contracts.”
But the Brits are left horrified when they later watch footage of Rob pulling a woman along by her hair in what is known as a “public disgrace” video.
Neelam says: “I felt like I’d been lied to. He’d talked so much about respect and choice and then we saw him doing the other side.
“When we confronted him, his argument was that people are into it.
“But I completely disagree with him and he has to think about the message he’s putting out into the world. For me, it’s always about the bigger picture.”
Neelam was just 12 when she first watched porn and says she would then view it “most days”.
She stopped aged 16 after noticing she struggled to become aroused when having sex.
Neelam, who is in a long-term relationship, says: “I realised this is the effect it can have so I stopped watching porn because real intimacy is so much more important to me.”
A third of young people surveyed say they’ve had riskier sex due to porn, while a quarter have felt pressured by a partner to do pornographic acts.
Roughly four in ten say porn has made them more concerned about how their genitals look, and one in five claim it made them consider plastic surgery.
Yet over half of those surveyed agreed that performing in porn is a good way to make money, and over a quarter would like to perform in porn themselves.
In Barcelona, they meet Ismael López Fauste, a porn magazine journalist turned police informant. He decided to leave the industry after witnessing “human trafficking, drugs, lots of violence and a lot of prostitution”.
Ismael tells them: “The point where I got out was when some of the girls overdosed on the set because they gave them drugs. I thought, ‘OK, I am a part of this’. This is just one of the stories.”
After writing a book exposing how some women are exploited, he says more came forward to tell their story.
But he adds: “Then the threats began because they wanted me to stop writing. They wanted me to delete everything.”
Asked who threatened him, Ismael replies: “The producers.”
He adds: “I want you to hear someone who was inside the industry. She was going to be with you but in the last few days she got threatened.”
The woman agrees to speak to the group over the phone. A former porn actress, she says: “In some scenes I was made to take drugs and if I didn’t I would be sent home without the money.”
She adds that she tried to report it to the police “but they aren’t bothered” and that she has failed to get the videos deleted.
The emotional interview leaves student Anna, from London, in tears.
She says: “It’s just really quite hard to know that it’s going on.”
A visit to a Madrid studio, run by director Torbe, the so-called king of Spanish porn, also leaves her shaken.
He tells them: “I find girls who don’t know anything about anything.
“Ninety-five per cent of the girls who come here are new, so I teach them, especially young girls.”
When the TV pals visit he is a filming a group sex session involving one woman and several men.
The star is a 19-year-old Russian girl who, the group are told, will earn just over £2,500.
She is wearing a red eye mask and her hair is in pigtails.
Her appearance is enough to prompt Anna to demand Torbe — under investigation for allegedly distributing child pornography — to show them proof of the girl’s age.
After seeing a copy of the her ID, Anna is satisfied but remarks: “She’s just turned 19.”
Filming is further delayed because the young actress — who reveals she has only been in the job a week — is so nervous.
As the 20 men, who wear masks to hide their identities, wait around on set, the Brits discover that the Russian girl had been expecting half that number.
Let’s pause here to take a look at the numbers, since porn-apologists make claims like, the women in porn make “a million a year”. Porn is usually paid by the sex act, £2,500 ÷ 20 = £125 per sex act, assuming there is only one sex act per man on set, so the £2,500 is actually a rip-off. There is no way anyone could do this kind of filming every day; women only last “six months to three years, tops” in the porn industry, and one analysis found that almost half of the women in the US porn industry did only one or two films before quitting.
When Anna, who stopped watching porn because she felt it did not fit with her feminist views, confronts Torbe, he says it is because they are shooting “two scenes” today.
When filming does finally start, Anna leaves the set in tears.
Speaking outside, she says: “I’m really concerned for her safety. I feel scared for us to leave because I don’t know what’s going to happen when we are not there.”
In the studio, Ryan has to comfort a tearful Cameron, who says: “It is the worst thing I’ve seen.”
Ryan adds: “It just doesn’t look fun. After a week, how do you know how comfortable you feel sleeping with this amount of men? It’s not the environment for a 19-year-old.”