If you're writing a romance, erotic or otherwise, and your characters are going to have sex, you need to create sexual tension between your main character and their love interest.
If you don’t create sexual tension, your sex scene won't mean anything to either your characters or your readers.
What is Sexual Tension?
It's not romantic tension.
Romantic tension is about the future. It's about building long-term emotional intimacy. The culmination of romantic tension should be the happily ever after or the happy for now.
Sexual tension is about getting it on. The characters want to get each other into bed or, according to George Michael, the sofa, hall, kitchen table, or outside. They're thinking, "I want you naked as soon as possible". For them, it's the feeling that getting it on will clear the sexual tension between them. For the reader, sexual tension raises (ahem) the question, "Will they or won't they?".
And to note—in a romance novel, romantic and/or sexual tension should exist between both characters. If not, one character simply has a crush on the other. Two people must feel attracted to one another romantically and sexually, but they don't—or can't—act on their feelings.
How to Show Sexual Tension
Eye Contact
The look of love is all very well, but what about the damn-you're-sexy-I-wonder-what-you're-like-under-that-shirt look?
A long lingering look, one quirked eyebrow, the hint of a smile offered over the rim of a whiskey glass? Catching the other character's eye, the look softening into a stare? That's the eye contact that signals sexual attraction and the longer it lingers, the greater the tension.
Touch
The urge to quote Little Mix's track 'Touch' is strong, but I must resist despite it perfectly summing up sexual tension and that super-tingly feeling when the main character and love interest indulge in a little 'accidental' leg brushing or hand lingering. If neither of them pulls away, the sexual tension is strong.
Something sexy this way comes (pun intended).
What makes the sexual tension even stronger? WHEN THEY MOVE EVEN CLOSER.
Change Their Voices
Be it 'sexy baby voice' or 'manly stud voice', our voices change when we meet someone we're attracted to.
Sexy baby voice might signal that a character needs taking care of because they're vulnerable. Manly stud voice might signal that they're the person to deliver said care because they're strong. Decibels up or decibels down, voices change.
And then there's the mortifying moment when the love interest asks your main character a question and the main character squeaks in response. Mortifying.
Victoria Browne, Mindset and Confidence Coach, says:
“Studies have shown our pitch changes depending on how we relate to the person we are speaking to and the emotions or feelings that we have or relate to that person. For instance, we will have a different tone, pitch, or rhythm to our dialect and even a different use of the language we choose to use with someone we are attracted to compared to someone we feel anxious around.”
and
“We make most of these changes subconsciously, but the reason behind it is about the way we want to be looked at or seen by that person. In terms of romance and attraction, we will try to almost copy that person matching as closely as possible to their tone, pace and speech patterns in order to 'connect ' with them and be seen as more desirable.”
Ramp up the Laughter
Here's something to think about: Is your character attracted to the love interest because they make them laugh or does the fact they're already attracted to the love interest make the lover interest seem funnier?
Who's the joker, and who's the audience? And which organs are they interested in exactly? Their sexual organs or their brain?
Using chat-up lines is (typically) a man's way of displaying their sexuality like some kind of hilarious peacock and it's the response to this that signifies sexual interest.
"Oh, Brad, you're so funny! My shirt unbuttons like this..."
Flirt, Flirt, Flirt
Flirting encompasses eye contact, touch, voice changes, and laughter, so I won't go into all of those again.
But let your characters flirt, okay? It's fun to read, and it's fun to write.
Make Them Dream
If the main character can practically taste the love interest's lips, they've thought about it—a lot, like sooo many times—they've got themselves some sexual tension.
If the main character can't keep their mind on anything during the day apart from how snug the love interest's clothes hug their body—they've got themselves some sexual tension.
If the main character gets up to something nasty with the love interest in an x-rated dream—they've got themselves some sexual tension.
Make Conversation Awkward
Has your main character got into a conversation with their love interest but forgotten their own name? That's awkward. Messing up the punchline of their favourite joke simply because the love interest is in their orbit? Awkward. Fumbling over the simplest sentence construction? Stuttering silence? Awkward.
And awkward conversations can endear the main character to the love interest, which infuriates the main character because they don't want to be cute and awkward—they want to look cool and impress the pants (literally) off the love interest.
Especially About Sex
Remember that for sexual tension to exist, two people must feel attracted to one another, but they don't—or—can't act on their feelings.
When sex comes up in conversation, it changes everything (see Make Conversation Awkward above).
Make It Obvious to Everyone
After seeing the two of them together, if their friends pull your characters aside and say, "WOAH, that was intense. What's going on with you two?" then the sexual tension is positively crackling.
Make Them Insecure
Remember that fast food binge your main character had last week? Maybe they put on a pound. Well, now they're chatting the love interest up in a bar and it occurs to them that if they're going to get it on, they might not be in tiptop condition for the sexual olympics. What do they do? Do they cool things down or pray that low lighting a sucking in their gut will do the trick?
And talking about the Olympics, what if the love interest is a marathon lover instead of a sprinter? Can the main character last that long?
Insecurities, people, we all got 'em. And the thought of bumping uglies will probably trigger your characters' insecurities.
Butterflies Aren't Only For Mariah Carey
Butterflies or food poisoning?
Your main character's physical reaction to the love interest makes them want to pounce. Norepinephrine, dopamine, and oxytocin make a character feel good and that stuff's surging through them.
And unless your main character has an ongoing stomach problem, butterflies in their tummy are a sure sign they've got an ongoing sexual tension problem.
They Smell So Goood
The love interest has that special brand of human smell your main character can't get enough of. It's basic chemical compatibility and not just that excruciatingly expensive eau de parfum.
To paraphrase Jennifer Rush, it's the power of musk. Call it pheromones or the heady combination of shower gel, shampoo, and fabric conditioner. Whatever the love interest is radiating, it's driving your main character to crotch-tingling distraction.
And they want to be around them, which leads us to...
Magnetic Gravity is Key
Wearing their best clothes to the local supermarket just in case the love interest might be there?
"Oh, hi. I didn't realise you shopped here at exactly 6.15pm every Monday night."
Ending up standing next to them at a social gathering?
"Oh, hi. I hadn't realised they'd invited you." Or that you arrived at exactly 8.17pm in a British racing green, limited edition Mini Cooper...
Does your main character know exactly where the love interest is in a room at any given time?
"Oh, them? I think they might be at the buffet, two people over from the woman in the red dress, just by the hors d'oeuvres."
(And just in case you think the main character's a bit of a stalker, chances are the love interest is thinking and behaving in exactly the same way.)
Challenge Each Other - "I Bet"
"I bet you're a rubbish kisser."
"Haven't had any complaints."
"Oh, really?"
"Yes, really. Maybe if you're lucky, you'll find out one day."
("I bet you can't fit an entire spaghetti squash in your mouth," is probably taking things a bit too far.)
Let Them Acknowledge It
Shoehorning the love interest into every single conversation is a sure sign your main character has it bad for their love interest. Plus, it will probably tip off even the most unattentive friend that something is up with the main character.
Why, oh why, does the love interest keep tripping off the main character's mouth at every given opportunity? (This also works for romantic tension.)
Don't Let Them Acknowledge It
Addressing the tension openly will kill it. Addressing it by giving in to desire is the payoff. Not talking about it is thrilling.
Un-Sexifying Them Doesn't Work
If someone's ever advised your main character to picture people naked when they're nervous about talking to them, that won't help with sexual tension. If anything, it will make it so much worse.
Final Thoughts
Without adding sexual tension, your sex scenes will lack impact. This is because there needs to be sexual tension in order for those scenes to matter to the characters.
So closing, if you're intending on writing sex scenes, make sure you add sexual tension from the moment your characters meet!