"She looked deep into his eyes and suddenly she felt his fingers running...."
...away with the typewriter, would be a good idea.
If your story involves any character higher up the evolutionary ladder than an amoeba, then the chances he/she/it is capable of having a bit of how's your father with another character, preferably belonging to the same part of the ladder.
It is natural, can often fit in with the story and nine times out of ten, if the sex is any good then it hopefully defies description. So why the hell do we feel the need to attempt to describe it?
I suppose my problem is that I have a bit of a comedy background and I cannot read any passionate sex scene without bursting into laughter; not a nice sort of laughter, but the sort that probably involves layers of derision and sarcasm, possibly a touch of pity (maybe even some self loathing, but that applies to a lot of us). Some of this has to do with zippers; there is something very funny about a zip, especially if you add sound. I always fancied writing a sex scene involving 1970s punks where by the time they finished with all the zips, they were so knackered, they gave up and went for a pizza instead.
To me, sex scenes really have to have some relevancy.
If you are describing a road trip, you would have to have a pretty amazing reason to describe in graphic detail every gear change and clutch pedal depression. Most people know how to drive a car and they know what happens when you go in one; you start in one place and probably end in another. The trip itself, what you see, what you hear, what you learn, might be very relevant to the story, but the chances are that the particularly smooth change from third to fourth is academic.
But when it comes to love trips, in all sorts of genres, there seems to be more and more demand to account for every single gear change.
Now, I am no prune, or prude, enough so that I actually do know what happens between two or more people given half the chance, but, it doesn't mean I want it shoved in my face, in any sense you want to take that. If my characters have sex for some reason that needs to be explained, I want to know why it is important. So I want to know that she was angry with him as she made him beg for more, I am not interested in how perky her breasts were. I want to know that the heat of the night made their passion more urgent, I do not want to know how whatever hair stood on end.
For characters to engage in any sort of sexual play means there must be a reason for us to be there; if there is not, then we don't need to go through the door with them,.
I started thinking about this the other day when someone asked me about something I am writing and wanted to know were there any sex scenes in it. It felt like they were saying that if it is for adults in any way, then it has to have sex, otherwise there is no market for it, or I am letting my readers down. I personally do not think that readers are that narrow minded for the most part. Oh, I know there are some that think something is only "dark" if the blood sprayed round the room or something is only "tense" if the lead male is suicidal, but I really hope that is a blinkered minority.
So, will any of my books have sex scenes in them?
Of course they will. But they will be short, they will talk about the emotion/angst/bitterness/resolve of the moment, and they will definitely not include any fingers running off with anything!