Take your average blockbuster and you'll find many feature a Hollywood heartthrob or starlet undressed and acting out scenes of passion under the covers.
But away from the A-list and the red carpet there is a whole industry dedicated to far more gratuitous and graphic displays.
In the 21st century pornography is freely available on the internet with politicians discussing ways to keep its potentially harmful content away from impressionable children.
Yet despite the glut of smut accessible online for free at the touch of a button from the privacy of one's own home there are still cinemas showing sex movies to audiences prepared to pay £8 or £9 a time to watch others having sex on camera. And some of them are right here in the West Midlands.
Film-goers even go online to discuss which is the best venue to visit.
They are not hard to spot though, at one such cinema in Bilston the words 'Foxy Dance Bar, Adult Shop, Adult Cinema' are painted in towering black letters.
Outside, a council notice is pinned on the door offering proof of the business' licence, affirming that everything is above board and legal. Another sign welcomes visitors into the cinema, explaining that the dance bar will open soon.
Once you venture inside heavy curtains block sunlight, and prying eyes, from penetrating the building. A tiny television set at the reception area is showing an adult film in full swing.
The man behind the counter says it costs £9 to go in. It is only 3pm on a Thursday, but once you've stumped up the entrance fee you can stay until doors close at 9.30pm.
There are two screens, and you can flit between them as you please. A sign at the venue says there are no sex acts allowed inside.
The man at the door explained: "We've got to put them up by law." Yet go online and you'll find tales of all kinds of activities that people claim to have indulged in while there over the years. The last was in 2011 and when we spoke to the owner he insisted no sex acts take place on site.
Councillor Bishan Dass, chair of Wolverhampton City Council's licensing committee, said the council had not received any complaints about the cinema, adding that were it to receive any, it would have the authority to revoke or suspend the businesses' licence following an investigation.
He said he had previously told the manager that the council 'would not be interested in anything that would bring a bad name to the city'.
He added: "He promised that, no, he was running his business quite within the law and within the licensing conditions. Since then I have heard nothing about Foxy Lady and unless somebody complains or we find something wrong there's nothing for us to do.
"We haven't heard any complaints from the locality – mind you it's all industrial; I don't think there are any residential properties.
"We know that it's very popular with punters coming from outside the city," he added.
Colin Parr, the council's licensing manager, added that there was a strict framework of regulations governing sex establishments in Wolverhampton.
He said: "The framework does give the public the opportunity to have a say on whether these venues are licensed or unlicensed and we receive very, very few complaints about the operations."
He added: "These are legitimate businesses used by consenting adults.
"What the licensing framework does is set up the mechanisms that take place in a way that protects the public and protects residents."
For example, he said, sex establishments are heavily restricted on what they can display outside, compared to, say, pubs and clubs, which have much more freedom.
Furthermore, the licences are subject to annual renewal involving public consultations, a measure he said was again far stricter than other licences were subject to.
"In terms of the 40-odd licence types that we issue as a service," he said, "sex establishment licences are amongst the most regulated that we have got. It essentially gives the council massive control over how the premises is run and it also gives the public a very strong say in the application process."
The actual cinema at the Bilston venue is in a dark room, covering about 30ft by 20ft with rows of faux leather seats, peeling wallpaper and a screen the size of a small billboard at the far end. A handful of men are dotted among the 50-odd seats.
Most are middle aged, casually dressed in jeans and T-shirts, but one older man soon enters wearing a three-piece suit. There are no women to be seen. On the screen is the sort of thing that is all over the internet – a pornographic feature with a plot in only the loosest sense of the word.
Everyone in the audience is sitting motionless, eyes glued to the screen, straining to hear the muffled audio. Again there are no women and it turns out that they are 'not allowed in' according to the man at the reception.
Back out in the shop are rows of pornographic DVDs, available to rent for £30, with a £15 refund upon return. You can almost see why in the 1970s, long before the internet, this sort of venue would have been popular.
As it is now, with all it offers available online, much of it free and at the click of a mouse, why do men still come to places like these?
There is no doubting many of those who use these cinemas can't get online at home. But another possible answer is waiting outside.
He's a 60-something man wearing a smart grey suit complete with polished black shoes and a pocket handkerchief. The man first visited two weeks ago. And in that time he's met 20 other men. Human contact is something the internet has yet to replace.