So. This is one of my first projects, so I have to ask this. The story takes place in a dystopian future, where a young man and a young woman meet each other. They then try to overthrow the tyrannical government, but that doesn't really matter, right? Well. I want to include sexual tension between the two, but I don't know how. What guidelines should I follow to write believable sexual tension between two characters?
Sexual tension occurs when two characters are attracted to each other, but where becoming a couple is impossible for one reason or another. For that reason, how you depict it depends on what the obstacle to their happiness is: Do they hate each other? Are they too dedicated to their cause to take time for love? Are they oblivious to their feelings? Are they from warring factions?
Depending on their personalities, and the nature of the obstacle, some of the typical ways people respond to attraction are: Flirting (this can come in many flavors, including innocent, playful, aggressive, courtly, hostile, seductive or raunchy), change in mood (becoming inexplicably happy, silly, angry, bashful, nervous, etc.), increased physical closeness (touch on the shoulder, backrubs, etc.), or even the opposite extreme of avoidance.
How it plays out is very individual. Let's say the obstacle is their all-consuming dedication to fighting the government. One partner might respond to their newly discovered attraction by getting angry, and avoiding the other. The other one might become silly and flirtatious. At that point, their opposing reactions can lead to new misunderstanding and difficulties. You don't have to overdo it, however. Readers love this sort of thing, and will happily read between the lines.
In our real world, couples almost always have sexual tension right before they are both certain that the other one wants to get physical. It's also a struggle when it's inappropriate for the two to have a sexual relationship so each person tries to deny the attraction.
I remember being a teenager and this guy kept "accidentally" bumping his hand next to mine as we were taking a walk. I knew he wanted to hold it, but I was terrified that there might be a very slight chance that he really was just bumping it by accident, and if I took his hand, he'd snatch he'd away and give me the "I'm very flattered, but ewwwww. No way!" speech.
I also remember that there was this boy I hated for over two years because every single time he spoke to me, he would sound like he was going to say something nice, but he'd end up saying something rude, obscene or otherwise personally offensive. One day we ended up taking a really long walk together alone for some reason and he just listened to me talk about my unrequited crush on one of his best friends. He ended up telling me that I was too good for his friend. I was totally confused by him saying this. He finally told me that for the last several years he had such a big crush on me that every time he tried to speak, something horrible came out of his mouth. We ended up making out, having intense sex and dated for four years. It only ended when I moved across the country and he didn't want to leave his family so he stayed home. He's still a great friend. I think we could have gotten married and been OK.
There are awkward moments where a friendly couple might be having a normal conversation or completing some task. He might accidentally notice she looks extremely attractive at a certain moment and become distracted. He unintentionally says something that could be taken as a sexual innuendo. She notices and tries not to respond or maybe attempts to turn it into a joke.
I'm not a fan of the witty one liners tactic for a book. In the movies or television, it works because the audience can't get inside the character's heads. But if you're inside someone's head and hearing their thoughts. They will be thinking about sex or trying very hard not to think about it. People aren't really ever totally blind to their sexual attraction right up until they grab each other and start making out in the middle of a fight. That just doesn't happen.
Almost everyone feels vulnerable and gets a little tense right before they begin to kick things up a notch. There's no need to go overboard with it.
Try and include a bit of wit between the characters.
Provide moments in your story whereby, there is a display of short and concise, witty one-liners. These are bounced between the characters like a tennis match, back-and-forth between the two.
To think of it abstractly - imagine a point scoring system, if one provides a short, succinct and humorous line - they score a point, the other retaliates. This is all in good jest and provides for non-hostile competitiveness. This competitiveness is where the sexual tension is derived from.
Tough question--especially if you've never experienced that type of thing. You might get quite a few suggestions here.
My own conclusion is to say that, by the end of the book, the reader wants them to get together: they have earned each other's love, respect, and admiration. There are thousands of literary and cinematic examples to help guide you. Whether they get together or not is up to you.
I think that sexual tension is reflected in scenes where the dialogue and actions have been put together in such a way that the reader can feel it. The actions of your character are an essential part of creating this tension. Don't say it, but make their actions show what they are feeling. Also, short interactions create more tension in a dialogue than long ones.
In the film Pride and Prejudice the main characters - as was normal at that time - have never touched. In fact they barely talk, they are struck dumb when they meet. The tension between them is enough to burn houses down. One day he has to help her into a buggy, and he takes hold of her hand. She drives off and he stands there looking at his hand. Mind blowing.
Tension (of any sort) lies in what doesn't happen. To create tension you create the expectation that something is about to happen, but then don't let it happen. This keeps the reader waiting for it to happen, and that is tension: waiting for something to happen that you expect, hope for, or dread.
There are all kinds of ways to make the anticipated event not happen. That part does not matter so much. It is really all about how much we want/expect/dread it happening and the timing of it not happening. Tension is like humor. 90% of it is timing.
So, sexual tension is simply sexual relations that you expect, hope for, (or dread) that don't happen. Create the expectation of relations, then deny them.