capturing authentic-looking sex on camera

isn't always straightforward.

Some films intentionally feature dodgy intercourse

to invoke humor.

But for the genuinely romantic depiction,

actors and directors can face a myriad of challenges.

Film sets are often packed, demanding, and tiring.

A far cry from the sexy mood you see on screen.

We caught up with a leading intimacy coordinator

to find out how sex scenes are filmed in movies.

Moviegoers generally accept

that the first ever on-camera orgasm

in a non-pornographic film

was in the 1933 Czech film "Ecstasy,"

a romantic drama starring Hedy Lamarr.

But it's only in the last few years that a specified role

to guide and coach actors for love scenes

has become mainstream.

One such coordinator is Ita O'Brien,

who worked on Netflix's "Sex Education,"

as well as HBO's "Watchmen."

Ita O'Brien: So, an intimacy coordinator puts in place

a structure that allows for agreement and consent of touch

with intimate scenes,

and then a process

that choreographs the intimate scenes clearly.

Narrator: Rehearsals start with a series of exercises

around consent of touch.

Actor 1: May I hug you chest to chest?

Actor 2: Yes, you may.

Actor 1: I put my arm around your chest.

Actor 2: I take ahold of your hand.

Actor 1: I take your hand with my hand.

Narrator: Ita will then

block the scene with the actors closely,

discussing the motivations

for each moment of sexual contact.

She also encourages productions

to create a positive on-set environment.

And actors do need protecting,

as love scenes often leave them vulnerable.

Maria Schneider accused director Bernardo Bertolucci

of emotionally assaulting her

by insisting on a now infamous rape scene

in 1972's "Last Tango in Paris."

And Salma Hayek

accused controversial producer Harvey Weinstein

of insisting on a nude scene in "Frida."

The first season of Netflix's "Sex Education,"

shot in 2018,

was the network's first production

to employ an intimacy coordinator.

The show features a variety of intimate content,

from masturbation to sexually charged confrontations.

Ncuti Gatwa: We had to watch videos

depicting different animals' mating rituals.

Aimee Lou Wood: Slugs. Connor Swindells: Slugs.

Ncuti: Lions, cats, dogs.

Aimee and Conner: Bonobos.

Narrator: To protect the young cast

from being naked on set,

Ita devised a series of cushions made from lamb's wool.

Ita: This stuff is the equivalent of the

stunt coordinator's crash mats.

You can just give another barrier

sort of by placing that in between.

So that means that they can be lying on that,

sort of in positions, and have it hidden.

But I actually used this as well

for a moment of simulated cunnilingus.

So, the actress was able to sit on that,

and it really gives quite a strong,

you know, and, again, it gives a sense of

a dress on over the top.

Narrator: Actors can wear varying layers

of flesh-colored underwear held together with tape.

Nipple pasties can be worn to cover breasts.

And, yes, they do even arrive in a headphone pouch.

Ita: The least that they would wear is this genitalia patch,

flesh-colored pant stroke shorts,

or flesh-colored shorts, like that.

So, this obviously then is a G-string for,

or a dance belt for a man.

So again, you've got a good cup in here.

Very often, of course, you do the wide shot first.

But in this, it's actually better if you do the closer up

so they can be more covered.

And then, if they can really find the flow and the rhythm

and the breath, and if they're completely comfortable,

and then they're like, oh, yeah, OK, fine, we'll take

the layer off, and then we'll take another layer off.

Narrator: But for these fully frontal moments,

female actors can also wear a merkin,

which is an artificial cover for pubic hair.

In an interview with Allure magazine,

Kate Winslet said that the producers made her one

for her Oscar-winning turn in 2008's "The Reader."

Choreography and clothing are important,

ensuring the actors look like

they're touching the right part of someone's body.

But directors can also give the illusion of intercourse

through camera movement or camera position,

cheating the shot.

Practical effects can also assist scenes by adding drama.

If two people can't keep their hands off each other,

why not add in a little thunder and lightning

or get them soaked in the rain?

Glycerin spray, oil, or water

can be added to the actors' skin

to give them that sweaty look.

And then there's some more extreme augmentation.

Visual effects have been used

to splice together the actor's face

and their double's nude body.

In Lars von Trier's "Nymphomaniac,"

actors' faces were superimposed

on porn performers' bodies using CGI.

And elements like props and music can be important.

Ever watched a film

and thought it was just tacky or unconvincing?

In the history of cinema,

there have been some unnecessary additions of props

like candle wax or ice cream

or people proceeding to accurately fire guns

whilst having sex.

A sex scene can also be ruined by out-of-place music,

like the inclusion of Leonard Cohen's "Hallelujah" playing

while Silk Spectre and Nite Owl make love

in 2009's "Watchmen."

Then there's the lovemaking that gets a weirdly paced edit,

like the lustless, mechanical movements

between Trinity and Neo in "The Matrix Reloaded."

And enthusiastic foreplay

that is better than the main event.

We're looking at you, Bella and Edward.

That's not to say that plain old bad acting

doesn't sometimes influence the outcome.

Actors here at Ita O'Brien's workshop

may go away with a changed perspective

on how to approach intimate encounters

by putting a series of safeguards in place,

being professional, and having fun.