One problem new writers have when they approach a sex scene is that they think of it as a SEX scene rather than a sex SCENE. Any effective scene — sex or not – serves multiple purposes. This is especially true of a sex scene, otherwise it will seem unconnected to the story, as if you just threw sex in the mix because you felt it was time to titillate your readers.
One good use of a sex scene is to show character. One of my favorite scenes in my novel A Spark of Heavenly Fire is when Jeremy King, a world famous actor, sleeps with a woman he just met in a bar.
The sound of weeping woke Jeremy. He turned his head toward his companion and saw one trembling shoulder and a tangle of gleaming hair.
He stretched luxuriously. The red hair hadn’t lied. The girl had been all fire, kindling a passion in him he hadn’t felt in years. The memory of it made him hard.
He reached over and pulled the girl into his arms. He smoothed back her hair and kissed away her tears, murmuring, “Honey,” and “Sweetheart,” and “Dear.”
“I’m such a terrible person,” she said, sobbing.
“Shh. Shh,” he whispered between tiny kisses.
Her arms stole around his neck, and her lips sought his. In a surprisingly short time she bucked beneath him, calling out his name.
You’ve still got it, King, he thought exultantly. Then, after one final thrust, he tumbled into oblivion.
I always liked that scene. It’s not very graphic, but it did what I wanted it to — define the characters
Another good use of a scene is to show the ebb and flow of human connection. For example, you could have three scenes spread throughout the story. In the first scene, perhaps, the man climaxes, feeling connected to the woman. When he immediately goes to sleep, she feels disconnected. In the second scene, perhaps he can’t get it up, leaving him feeling disconnected, but since he tries to make it up to her by cuddling her, she feels connected. In the third scene, they climax together, perhaps cuddle afterward, so they both feel connected.
In addition to the sex, then, you show a pattern of connection and disconnection between the couple (in other words, conflict), you show a whole new perspective of the characters, and you show a change in their relationship. You also end up with a subplot that adds to the overall richness of the story. In other words, you end up with a series of sex SCENES, not just SEX scenes.