As I had said last time, a good, believable sex scene is important. If you want a refresher on last week click here.
Now to continue. One of the biggest pitfalls is the words used in the scene. Try to avoid clichés such as “throbbing member” or “Hard as steel”. At the same time, don’t sound too clinical by saying “labia” or “penis”. Call it what it is. You want your reader to read the scene smoothly without getting distracted by strange words like ‘his hard salami’.
But how do you know if your scene is doing work to the greater body of work?
Easy, if you can skip past the sex scene and not lose any important details or emotional changes, then your scene isn’t doing enough work.
Your characters should always have a change in their relationship, whether that change is being more physically intimate or more emotionally connected. There should always be a change. Not only should there be a shift in the scene, your characters should have some reaction to having had sex with their love interest. Do they feel closer to their love interest? Does it scare them away? Does it make them emotionally shut down?
Just like every good scene, your character’s should evolve by the end of it and the plot in some way must have moved forward.