Because she is a writer, she would like there to be more of a plot to the way it all works out in the end. She knows how it’s supposed to start, with her establishing her normal life – which, in this case, is the fact that she never manages to come during sex – and then immediately move on to how she tries to fix that.
The truth is, though, that she doesn’t try to fix it, not for five whole years. She’s content –more than content – with the sex, not least because they’ve discovered other stuff that turns her on: biting and bruises and giving head, to name just a few of them.
Already, as a story, it’s way out of shape.
At the midpoint of the story, she should already know what the ending will be – she should be foreshadowing that ending a bit. But there is no foreshadowing, because the situation remains the same. She is no closer to orgasm than when they began.
After that, things do get a bit more plot-heavy. They start to try things. Toys, porn, his fingers on her clit, her fingers on her clit. She doesn’t enjoy any of it. It’s just a distraction from all the things she does like about the sex.
So they stop trying. Bad, from a sex point of view, perhaps, but good from a story one. This is the darkest moment, the point where everything the heroine is trying to achieve seems beyond her reach.
And then, one day, when they are not trying to make her come, either of them, when he is on top, and her leg is on his shoulder and they are kissing and her hips are thrusting back towards his, she does come, just like that. Pure serendipity.
Bad, from a story point of view, perhaps, but good, so damn good, from a sex one.