When watching a movie and it starts to get a bit steamy, the last thing you're thinking is if the characters are actually doing the deed.
While Hollywood's elite are paid a handsome amount to make you believe they are in fact having sex on screen, most of us know that isn't actually the case.
Or at least, we thought we knew.
Yes, there have been a handful of actors who have come out to explain they actually went to fourth base with their co-stars.
So, if watching sex scenes in movies with your parents in the room isn't awkward enough, some of them could be classed as a porno!
Now, let's get into the full list of bizarre movies where actors have real unsimulated sex in them - created by someone on Letterboxd, the social platform for discussing films.
For those of us who are unfamiliar with the terminology, unsimulated sex just means the 'actors' are going the full hog on screen.
The 276-strong list features some movies you'd expect, like Caligula - the infamous movie that incorporated so much sex, it had to drastically cut out before being allowed to take it to the big screens.
Caligula is a historical epic starring Malcolm McDowell and Helen Mirren, produced by the creator of Penthouse magazine who edited his own hardcore sex scenes into the movie (Analysis Film Releasing Corporation)
The 1979 film was banned in several countries, including the US, with police in its home country of Italy labelling it 'flagrantly obscene'.
While most of the list is padded out with films that don't necessarily have the blockbuster budget, some notable names on the list are Antichrist, I Am Curious (Yellow) and Starlet.
Antichrist starred Willem Dafoe and Charlotte Gainsbourg, and it featured their characters having unsimulated sex on screen.
But if you thought you were going to see the Green Goblin knock his socks off on-screen, then you'd be sadly mistaken, as the 2009 horror actually employed body doubles to do their dirty work.
The Letterboxd list wouldn't be complete without Antichrist on there (Curzon Film)
When asked about the scenes, Dafoe explained that both he and Gainsbourg were married when they took on the roles, pointing out: "I’m not sure everybody would be cool with that."
One film that didn't make the list was the 2013 flick The To-Do List - starring Aubrey Plaza as high school student Brandy Klark.
Plaza, who was 28 years old at the time she was portraying the teen, admitted in an interview with Conan O'Brien that she pleasured herself on-screen after initially thinking that the scene in which she did so would only show her hand going 'slowly go out of frame'.
She recalled: "I asked the director 'what should I do' and she said 'masturbate like it says in the script'."