This morning I was thinking about sex scenes.
Not in that way, so don't get your knickers in a twist. I was wondering about their use in writing, how much is too much, how explicit is too explicit, and so on. Note that I'm excluding, for the purposes of this discussion, outright erotica -- writing that is intended to arouse. But what about ordinary, mainstream prose?
My general attitude is that there's no reason to avoid any mention of sex, out of some sort of left-over mid-Victorian sense of delicacy. Being part of what adults do, it's no more off-limits to write about than anything else that adults do. However, like any other kind of scene we could write about -- be it violence, farce, tragedy, anguish, comedy, or philosophy -- it can be overdone, or done poorly. Given that it's something that most people think about pretty frequently, and have (ahem) strong feelings about, if you do include sex in your writing, you want to get it right. I don't know about you, but there's nothing more cringe-inducing than a badly-written love scene. I don't think it's an accident that there is no contest for the year's worst fight scenes, but there is one for the year's worst sex scenes (to read about last year's winner, go here).
To me, a well-placed (and well-written) love scene works to dial up the tension in a plot. It can act as a point of happy relief when two characters you've been hoping would hook up finally do, or an "oh, no!" moment when two characters whose actions are leading them to disaster, and who should avoid each other like the plague, make it worse. And in my opinion, there's nothing wrong with its being, if not exactly explicit, at least thoroughly described. Like anything we write about, the point is to make the reader feel like (s)he is there, and is on some level experiencing what is happening to the characters. I see no reason why this kind of scene should be any different.
You do have to be cautious about descriptions, here, however. Most of the winners of the worst sex scenes contest won because of, shall we say, bad analogies, usually involving sounds, movements, or body parts. Keep it real. Keep it simple. Avoid purple prose. All of which are rules that could apply to just about any type of writing, but are especially important here. If your intent is to heighten the tension, dramatic and otherwise, it's a little counterproductive to cause your reader to roll his/her eyes, or worse, dissolve into guffaws.
Also, consider whether it's actually important to what's happening in the story. Like anything in writing, love scenes should be used judiciously. A pair of characters who seem to do nothing but to go for rolls in the hay eventually leave the reader thinking, "Don't you ever vacuum the carpet, or mow the lawn, or cook dinner? Or go to work?" Anything that causes that reaction is to be avoided -- the last thing you want is your reader suddenly getting yanked out of the story, and thinking, "Real people don't act this way." At that point, the world of the story has collapsed, perhaps for good.
I've only written two stories with sex scenes. One of them, in Kári the Lucky, was supposed to be tender, to make you feel sorry for the two main characters, a husband and wife who loved each other dearly and who you knew were headed for tragedy. The other, in The Conduit, is supposed to scare the living hell out of you, because the main character is making love to a guy who looks exactly like her husband -- but isn't. I spent a long time writing and rewriting these scenes, because I thought each one was an important juncture in the story, and also because I don't want to win the Worst Sex Scenes Contest of 2011.
However you handle writing about The Deed, it should be done with thought -- and like anything in good writing, considering how it adds to plot and character development. Throwing in a sex scene just to titillate is an insult to the reader. But handled with a deft touch, it can heighten the dramatic tension in a particularly visceral fashion.