I take the votes with quite some grains of salt, and I'm aware that looking at a single story's score tells almost naught. I do use them as a comparison tool to see how different techniques, perspectives and choices of words may tickle the readers' fancy, but that requires stories in the same category and with similar topics to work.
That said, I'm very much with the majority here and try to score based on the literary quality and not on the topic and setting. And I never vote on topics that are totally out of my comfort zone (not that there are too many of those).
I've got a whole bunch of fragments from just scribbling away without true aim when I can't seem to find the words to continue on the "big" pieces or when an isolated idea just begs to be brought to paper. I started doing that as a preparation for NaNoWriMo, to see if I had a chance at all to meet a certain word count in a given time even if my muse left me hanging. A number of those fragments have taken on a life of their own already. Most of my stories here on lush are built on them, small detours from those two 70k novels which are resting on my harddrive and pleading to be revised and edited.
I'd like to disagree with Nabokov, stonedcrab. Even if it hasn't been done, or not in a way that found appreciation, there is no reason why a pornograhic story could not also be high literature. In my opinion, the wall that divides pornography from literature is quite a thin one, and always moving. Examples like the Diaries of Fanny Hill or Henry Miller's works illustrate that once popular morale has shifted enough, a formerly condemned novel becomes an accepted and in some cases even even highly acclaimed piece of literature.
To come back to the original question - to write sex differently, write a different story. Just a little bit of plot is enough to make characters react in a different way, have different feeling and thoughts. Don't get stuck with the main event, like in a good meal, its the spices and colors that count. We readers know what a cock looks like, but we're not aware of the birth mark on its owner's hip and that his pubic hair has a touch of red in it, and when we try to wrap our lips around the tip of the cock to start our first ever blowjob, we might just be startled by the chime of the old wall clock and lean forward a bit too fast, which makes us take it deeper than planned and gives us that startled deer-in-the-headlight look. Add the unexpected, like chillie flakes on a roasted banana or balsamic vinegar in the strawberry dessert. Make it a question of not what happens, but how it does. Play with circumstances, drop a few conflicting emotions into the mix and stir. Play with intensity. A climax can be hard, forceful, or soft and sweet. It can be loud, filled with grunting and shouted obsceneties, or quiet, with suppressed moans. It can have your skin tingle, your nipples burn, your eyes water, or just be a vulcano erupting from your loins. And don't stop here. Sex is, mostly, not over that quick. There are aftershocks traveling through the body, there's sensitivity that makes each touch sweet torture. There's this bunch of butterflies dancing under your skin and making you weightless. There are thousand emotions that combine with the deep satisfaction to form the unique experience of blissful afterglow.
My solution to the formerly all too frequent bouts of writers block is keeping a word count and changing my writing aim to avoiding stagnation. I've got a huge folder of unrelated snippets and openings to which I add when I'm stuck with my stories. If I haven't managed to continue one of the "real" stories for ten minutes, I open a blank document and simply start typing whatever comes to my mind, either a situation between people that pops up in my mind or just a completely mundane moment that happened over the day, and on really bad day, just strings of random words pushed into a correct grammatical order. It really doesn't matter, and once I've managed more than 100 words, I allow myself to stop. More often than not, this is enough of an igniting spark to give me an idea for one of my ongoing stories, but if not, I doesn't matter either. Once I'm done, I add the new writing to the word count and am happy that it has increased. At first it may seem a bit unimpressing, but, as time goes by, a week of writer's block isn't a week without writing anymore, but rather a week of slower rising word count, and three weeks of blockage still make 3000 words.