(Also, my responses are colored by this post over here and its comments, which of course I did find because I am the Devil, and if you speak my name I appear. I think it's also an excellent post, and not just because the writer says that I (and Lois, to close the circle entirely) write decent sex scenes.)
The comment in particular I disagree with is this one, from kalimac: (By the way, I ask my loyal readers please not to go descend en masse upon this poor person who is nattering away in sie private journel. Y'all can be a little overwhelming, I'm told, en masse, and since I found sie via the magic of ego-google, it seems like a mean thing to do. *g*)
This is asking the wrong question. It may be sometimes necessary to know that characters are having sex, though you're better off guessing. It is never necessary to see them doing it, any more than it's necessary to follow them into the bathroom to know they're doing that.
I've certainly written a few scenes that involved trips to the bathroom. They weren't routine trips to the bathroom. (There's a puking-and-head-holding scene in One-Eyed Jack that I'm mighty proud of, and which is probably going to end up on the cutting room floor, alas, because it's meant to model a certain kind of hurt/comfort fic (One-Eyed Jack is the fanfiction novel in the Promethean Age universe) and it bears insufficiently on the plot, la.)
And there's not much reason, it's true, to show routine sex, unless you are doing it to establish a baseline. But I think the attitude that it is never necessary to show sex in fiction stems from the very mistaken idea that sex is only there to do one thing, that it only serves one narrative purpose. And of course, like every other kind of scene, it serves thousands. Romeo climbing into bed with Juliet, in other words, serves a very different narrative purpose than Oedipus climbing into bed with Jocasta. But I can certainly see why you might make the narrative choice to show each of those things.
(I can think of two really effective and fairly graphic movie sex scenes without trying--there's a scene in Boys on the Side where you can practically hear the audience chanting "don't do that, don't do that" under their breaths--it's the tensest moment in the movie, frankly: tenser than the murder--and there's one in Cooler that is my single favorite movie sex scene ever. It is really graphic, as far as non-pornographic movies go, and it not only tells you everything you need to know about the protagonists, it humanizes them and makes them beautiful. Let's see. Without straining myself, there's also narratively useful sex in A History of Violence, Trainspotting, A Clockwork Orange, Kinsey, Brokeback Mountain....)
Squeamishness, in other words, does not make for good literature. The purpose of the artist is never to look down.
Anyway, digression endeth.
commodorified is more interested in talking about the purpose of sex in erotic writing, but what she has to say is well-worth reading. (And you can feel free to go clamber all over her comments. She's here with informed consent. *g*) Here's a taster:
So I'm mapping this to 'subgenre', as in the differences between, say, the difference between cozy country-house mysteries, police proceedurals, the detective-centric mystery novel of character, and the overtly literary mystery that wants to state a broader theme.
Sometimes you describe the blood spatter minutely. Sometimes you just say there's a body.
So, when I said this job is like playing whack-a-mole? What I meant is, there is always some other little job that needs doing, and they proliferate while your back is turned. And they all have deadlines. My big job for this week was finishing the New Amsterdam draft. However, before Christmas, I still have to get through the entire thing on a revision pass; I have to do galleys for "Tideline" and review the contracts (It's appearing in Asimov's, my first story there ever); I have to revise the emergency last minute 1500-word review I wrote last night (today); and I have to be ready to do the proposal for Dust by Jan 15. Then I have to deliver "Periastron" by April 1 (it's a novella), and I have to have finished drafts of Dust and All the Windwracked Stars by the end of the summer.
And there will be other jobs. Galleys and revisions and contracts and arguments and (sex and sex and sex and sex and *stuffs Mick back into the box* sorry) and keeping this thing interesting and my monthly column for Storytellersunplugged.com (next one due January 6) and...
...and of course the business of living.
Gimme that hammer. WHACK!