IT’S what many people fantasise about - hanging out with a bunch of stunning porn stars at an X-rated shoot.

But what really happens on an adult movie set?

Porn is big business, with online adult sites receiving more hits than Netflix, Amazon and Twitter combined every month.

The industry is worth an estimated $97 billion globally - but its darker side has been well-documented, including earlier this year when five porn stars were found dead in the space of three months.

Many may envisage scenes of wild orgies, crazy partying and sleazy porn producers - but what's the reality?

Most of the industry’s best movies are made in the quiet LA suburbs of the San Fernando Valley so Sun Online spent the day there on set to find out.

"Private School", a lesbian erotic film set in a classroom in the 80s, is the latest offering from production company Gamma Films and is directed by the award-winning female porn creator Bree Mills.

'Does anyone need a douche?'
We're in a huge California mansion which is used for filming mainstream movies as well as porn.

The centrepiece of the purpose-built set is a teacher's desk - on which most of the “action” will happen.

While the crew build an authentic classroom, make-up artists get to work on the actresses and cameramen get their equipment ready to shoot.

A crew member pops in to deliver everyone’s Starbucks order and I start to feel like this could be any other TV or movie set - before he pops back in and asks casually, "Hey does anyone need a douche?"

To the uninitiated a douche is a small pump full of water or other fluids to eliminate odours and ‘clean’ the vagina.

In porn it’s an essential off camera tool and today is no different.

"Yes I’ll take one," said one actress just out of make-up. The rest say they have come prepared and brought their own.

It takes two to three hours to get all the performers through hair and make up and into their costumes.

'Who am I f***king today?'
The girls are loving the 80s theme - with brightly coloured eye shadow and crimped hair being a change from the usual glam porn make up.

I’m amazed how naturally beautiful the girls are - there are no fake porno boobs or bum implants here. And everyone is super-friendly - there's no bitchiness at all.

The conversations go from the kind of every day small talk about commutes and last night’s TV - familiar in every workplace - to conversations you could never imagine having with a co-worker.

“So who am I f***ing today?” the glamorous Georgia Jones, with hair up in rollers, saunters in and asks.

“Me and Emily,” Aidra Fox, 23, a pretty brunette, replies as she’s getting her make up done.

“Who’s Emily?” she asks.

“I’m Emily,” stunning Emily Willis looks up from her phone and introduces herself.

“Oh hey nice to meet you,” Georgia, 30, says smiling.

At 30, Georgia is a veteran of the industry. She shot her first scene at 18 and moved to California following a stint working as a dancer in a strip club.

Aidra also joined the industry at 18 after working as a web cam girl, while newcomer Emily only started earlier this year - after an ex-boyfriend persuaded her to shoot a scene with him.

Another girl comes in and asks, “Hey do I know you - did you do that 11-girl b*** j** with me?”

“No that wasn’t me,” Georgia says laughing. “But it sounds fun.”

Missing ping pong balls and slipping on oil
I ask everyone for their funniest - or cringiest porn moments.

“I once got a ping pong ball stuck in my vagina - they were trying to get it out with a spoon,” 20-year-old Emily giggles.

“It was actually awful, I was crying.

“They were telling me to push down like I was giving birth - but I’ve never given birth how am I supposed to know!

“Eventually the producer had to put some gloves on and get it out.”

It's after midnight before the crew start shooting the sex scene“My funniest moment has got to be when I’ve been all oiled up,” Aidra says. “There is this trend right now for very oiled scenes, where the girls are very shiny and covered in coconut oil.

"But you get very slippery so you’ll be in a certain position and all of a sudden your hands just give out and you just slip underneath the person or whatever. That’s always pretty funny.”

The two make-up artists laugh, “These are pretty standard stories for a porn set - we’ve heard it all before.”

The hair and make-up duo proudly describe how their make-up can withstand the most rigorous of adult scenes and how the girls rush up to them afterwards to tell them “Look I just did X and X and X and my eyeliner is still on!”

Make-up sponges as tampons
The worst thing about working a porn set for make up artists, they claim, is running out of make up sponges - as the girls use them instead of tampons so they can still have sex while they’re on their period.

I'm told some girls prefer not to shoot during their time of the month, while others are happy to carry on, keen not to lose out on potential earnings.

Within the adult entertainment world, female talent typically get paid between $800 and $1200 (around £600 to £900) for a day's filming - and the girls make their own schedule depending on how much they want to work.

Sex is still hours away
At around 1pm, almost everyone is ready to shoot but they are still one girl down - and are starting to worry.

“She claims she’s been partying with Jay Z last night so can’t make it,” one producer told me.

“But I’ve heard every excuse in the book.

“It just sucks for everyone else who has made the effort to get here - it can really delay filming.”

Eventually a replacement is found after calling round the various agents.

I wonder if it will be a little weird watching the girls I’ve hung out with all morning get naked and down to it - but then I’m told we are still hours away from any sex.

“The sex is the very last thing we film - just because it takes so much energy we need to have everything else wrapped up first,” says Bree, who is one of the leading female pornographers in the business and runs a tight ship.

Improvising scripts and sex scenes
Surprisingly there’s no script as Bree prefers to write the story, then “workshop” it with the actors.

“It’s great because it gives the actors a chance to be actors - which is good for them personally because many of them acted before getting into the industry,” Bree explains.

“It also stands as a testament that sex workers, actors and actresses are not just here for their bodies.

“It’s remarkable to see them take on these characters often with little to no prep, put on amazing performances and then outdo themselves by putting on amazing physical performances too in terms of the sex scenes.

“I like to be able to focus the day on acting and set the stage, get the performers into their characters and then let that fluidly go into a sex scene.

“It’s something that my mainstream counterparts can’t do - but we can. What’s to say we can’t make a good film and include sex in it?”

Personal boundaries and comfort zones
Following the spate of porn star deaths in the last year, actresses spoke out about bullying and depression within the industry and claimed porn bosses needed to do more to look after the health and well-being of their workers.

Bree says that on her sets, she works hard to make sure everyone is looked after, no one feels disrespected and regulations regarding age and consent are strictly followed.

In California, the industry is highly regulated with performers having to get tested for sexually transmitted diseases every two weeks and producers having to have official documentation that everyone is over age. They are even required to reference that the girls are all over 18 in the movie script.

Bree says that while there are good people and bad people in porn - like in every industry - she rejects the notion that porn is a "negative or shady space for women".

“As you can see there’s no wild orgies going on, there’s no people streaking and running naked and partying. It’s work, we’re here to do a good job. It’s a creative work but it’s work nonetheless,” she says.

“It’s very professional and we work hard. We try to make sure we take care of our cast and crew all day making sure there’s food and coffee runs and energy drink runs and that everyone has everything they need to be comfortable.

“It’s also a place of respect, making sure that everyone who is here is here because they want to be - we’re not doing anything that goes across anyone’s personal boundaries or comfort zones.

“It’s a big conversation we have before any sex to make sure everyone is comfortable and they have expressed what’s good with them and what’s not. So it’s clear for everybody.

“That’s something that I think often gets overlooked - everyone thinks it’s a place where people are taken advantage of, people aren’t in their right mind or they're sex-crazed youngsters but it’s not like that at all.”

Of course not all porn sets are as regulated and professional as this one - and the industry is often associated with the exploitation of women.

Many of the girls revealed how they avoid shooting in Miami which has more of a reputation for unregulated and "amateur" style shoots - often comprising of just a man with a camera in a hotel room.

And while all of the performers on this shoot said they had only good experiences in the industry, they were all aware of the need to safeguard themselves - by having reputable agents and only shooting for established production companies.

"We always make sure we know who we're filming with and what we will be doing before we even get there," Aidra said.

'We know what each other likes'
On the set of Private School, the cast and crew couldn't be more professional, working from around 10am until the early hours of the morning, practising scenes, shooting, then re-shooting until everything is perfect.

It’s a long day and can involve a lot of hanging around - the girls keep their energy up between scenes with pizza, Red Bull and coffee.

They also busily update their Twitter and Instagram profiles with sexy “backstage” pictures - these days the success of a porn star’s career in a super-competitive industry often dependent on their social media reach.

It’s after midnight before there’s any sex whatsoever - and for some of the girls this might be there second or third shoot of the week.

The girls take a quick break so they can “prep” which means douching, brushing their teeth, having a quick clean with baby wipes and washing their feet.

The scene’s star, the busty headmistress played by Angela White, tells me: “There’s like long term prep and short term prep - so in the long term we’re going to the gym, tanning, getting our hair and nails done - it's a lot of maintenance.

“Right before the scene there’s also a lot of prep depending on the scene.

“For this scene it’s just vaginal girl-girl so there’s no need to do an enemas or anything to prep the butt hole. For this we just need a water douche and a baby wipe. Most girls will put on some lotion and perfume, brush their teeth, mouth wash.

“We show each other our tests - to show we’re healthy.

“We’ve already spent the day together and developed a chemistry and here in LA it’s such a small porno family we’ve often already worked with each other and got to know each other’s likes and dislikes - so it’s just like getting back into bed with someone.”

Finally everything else is done and Bree announces - to the delight of the girls - that it’s time for the sex scene - “Godspeed everyone” she says.

The sex scene is the quickest part of the day
It’s almost 1am but the girls energetically - and rather impressively - start having sex.

It takes less than five minutes for them to all get naked and it's not long before four of them start pleasuring each other on the desk.

“We all look forward to the sex scene,” Aidra told me earlier. “I would say just about all of us joined the industry to have sex and to explore that side of us.

“There’s very few of us that joined the industry to be actors or models or anything like that.

“So for us it’s like: 'let’s get all of this other stuff over and done with we want to get to the sex scene now'.”

The sex scene is actually the quickest part of the day and takes around 30 to 40 minutes.

There’s no awkwardness, the girls have already talked before hand about what they like, what they don’t like and what they really love.

It’s the only scene that is shot only once without breaks or retakes.

“I never try to direct the sex because it really interrupts the flow and the energy of what’s happening organically,” Bree explains.

“Anyone who has ever seen a sex scene being filmed walks away really respecting the performers.

“It takes around 45 minutes so it’s physically demanding.

“It’s often on a unconventional surface - not always a bed or a sofa so it’s not always comfortable.

“It’s a long time to keep your head in that space. This is not like sex in your personal life, it’s definitely a performance and it's something that you soon realise as you’re watching ‘I wouldn’t be able to do this’.”

And while the girls all admit they love their jobs, they warn it’s not for everyone.

“I have really enjoyed my time in porn - I love being able to explore my sexuality and exhibitionism and celebrate my body but for anybody who has any shame about their body or their sexuality it’s not necessarily a positive work place,” Angela said.

“It takes a certain type of person - it’s definitely not for everyone. And there is a lot of stigma attached to this kind of work from society. I'd say the stigma is the worst part of my job.”