The adult movie industry in Los Angeles generates nearly half as much revenue as mainstream Hollywood, but it was dealt a blow recently when five actors were diagnosed as HIV-positive.
We had our invitation, street name and house number. All that remained was to agree a time.
Los Angeles in California is home to a thriving porn industry
"Come early," our host advised, "before the orgy begins."
And so I found myself at a large secluded house one chilly Wednesday morning, producer and cameraman in tow.
Expensive cars dotted the driveway. By the front door, two bored looking technicians were adjusting the lights.
To one side a long veranda afforded a panoramic view of the San Fernando Valley, capital of America's adult film industry.
The grand piano was decked with family photos of a middle-aged man, his wife and child.
The man in the picture appeared from the kitchen.
It turned out he was an accountant who had taken time off from attending to his clients' tax returns to watch as his palatial home was transformed into a porn set.
Where was the woman in the picture and the cherubic child, I wondered?
"Staying with their in-laws."
Were they aware of what was going on?
The accountant smiled. "I told them we were filming an exercise video - well it's a form of exercise isn't it?"
The director of the shoot, Paul Thomas, looked a little like Burt Reynolds' character Jack Horner in the film "Boogie Nights" - a movie all about the California porn industry.
Mainstream Hollywood is still the biggest player in the movie industry
Now 53-years-old, Thomas is virtually unique among his porno peers as someone who not only had mainstream ambitions but the talent to realise them.
The young Paul Thomas starred as Peter in the film "Jesus Christ Superstar" as well as on Broadway, before tiring of the constant auditions and falling into a more lucrative, less demanding means of making a living.
Famed for making plot-driven sex films, he is now regarded as the Fellini of adult entertainment and is now under contract to Vivid Video.
It is the biggest company in the business, and one of the only producers in America which requires its male performers to wear condoms on the set.
As Paul Thomas' wife sat knitting a scarf in the corner, I asked the two performers, 18-year-old Lexi-Marie and 27-year-old Trent Tesoro, what they made of the condom-only rule.
Trent, a former chef who intended to spend no more than three months in the porn industry, but three years later shows no sign of returning to the kitchen, said that "like most men" he preferred not to wear a condom.
He also works with production companies which do not have such strict rules as Vivid, and boasted that he had probably had unprotected sex "hundreds" of times on film.
Lexi, whose surgically-enhanced breasts lent an almost cartoon-like quality to her willowy frame, said she would have unprotected sex on screen if she "got to know someone really well".
As the day wore on, Trent coyly confided that he harboured a secret desire to get to know Lexi really well.
Like a teenager with a crush he told me he had a date with her on Saturday night.
He seemed much more nervous about that than having sex with her in front of a room full of people.
Condoms became an issue in the San Fernando Valley eight months ago when one of the industry's major stars, Darren James, tested positive for HIV.
Fewer than 20% of porn stars currently engage in safe sex
Four women he had worked with were subsequently diagnosed, prompting a scare which brought the entire industry to a standstill for two months.
It was the first such outbreak for many years, and the publicity it generated spurred state authorities into action.
Officials from the Californian Health and Safety at Work division imposed 30,000 dollar fines on the two production companies at the centre of the outbreak.
And there was even talk of enshrining condom use in law.
Yet for all the brouhaha, it is estimated that fewer than 20% of porn stars currently engage in safe sex.
The performers blame the producers, maintaining they would not get work if they insist on using condoms.
The producers blame the performers, and cannot believe they have not banded together to demand that condoms be used.
Back on the set, as Trent and Lexi were rehearsing the rudimentary dialogue that would serve as a brief prelude to a vigorous bout of sexual gymnastics, the director was distracted.
The porn industry has capitalised on LA's glamorous image
Paul Thomas had lost interest in the mechanical movements and blunt choreography of his shoot.
There was a problem, he was short of a body - would I like to help?
The crew explained what was required and I dutifully signed the release forms, pondering for about half an hour what my "stage name" should be.
I settled on "Dirk Diggler", the name used by the gauche waiter turned porn star in "Boogie Nights".
Then I sat back and did what everyone does on movie sets, legitimate or otherwise, and that is wait.
Had I known of my impending 15 minutes of fame when I met her a few days earlier, I could have got all the tips in the book from Sharon Mitchell.
The star of more than 1,000 sex films, she finally decided to call it quits when an obsessed fan attacked and raped her on her doorstep.
She returned to school to study for a doctorate in human sexuality and went on to found a health-care organisation which tests porn stars for sexually-transmitted diseases.
It was her clinic which detected the recent outbreak of HIV.
"Anyone with a handful of Viagra and a Hi-8 camera can be a porn star nowadays," she told me matter-of-factly.
"But most of the people who gravitate to this industry do so because they can't make it in the real world. They can't organise lunch let alone crime. Those are not the sort of people who learn a lesson."
When I inquired of the companies at the centre of the HIV scare, whether they now insist that their performers wear condoms, I was told it was up to the individuals involved.
State legislators know that, by cracking down on condom use in the San Fernando Valley, they run the risk of forcing the industry underground and forfeiting millions of dollars in taxes.
Before you ask, my career as an extra is on hold.
They ran out of time to film the scene while we were there and I thought better of returning the next day.
For those like Lexi and Trent, who have made pornography their lives, HIV remains an "occupational hazard".
One the love-sick Trent is desperately hoping will not sabotage their burgeoning relationship.
They have already had the sex.
All they need now is the love.
From Our Own Correspondent was broadcast on Saturday, 1 January 2005 at 1130 GMT on BBC Radio 4. Please check the programme schedules for World Service transmission times.