How to write a believable sex scene
Sex scenes are my favorite! My normal advice is to write better sex scenes, have sex.
Sorry, that might not be the best help, so let me see if I can break writing the scene down.
The sex scene has to be integral to the story, meaning if you remove the scene, the story doesn’t make sense. It also has to move forward the plot, not just be thrown in there without thought. Having it an essential part of the story makes it believable and honest.
After deciding that the scene is integral, I pick a tone. Is it a hot quickie? First time together? Are they reconnecting?
If the characters are awkward, it’s great to have an awkward scene. Often a sex scene can read like an action sequence. Or it can be a time of secrets being spilled along with, ahem, other things. Nevermind.
Anywho, the tone dictates word choice, length of the scene, and choreography. Depending on how graphic you want to be, the writing can be impressionistic or a play-by-play. It’s more important to stay true to how the characters act and ensuring that it’s a key part of the story, than making sure any specific description is in there.
I always need feedback on my scenes. My beta readers will point out things like, “he still has his pants on, so how is he doing THAT move?” Or “I thought she was facing the other way?”
There isn’t only one way to write a sex scene. If you’re true to your characters and plot, the scene will be believable and honest. Have fun!