Taken from the Writer's Evolution blog which hosted this excellent topic this week.
By Mia Watts
As someone who writes character driven stories, my answer has everything to do with what the characters would want. If Mavis is especially hot for Marvin and they finally get it on. She will not suddenly become inhibited or withdrawn. No, they will go at it like bunnies. And while I've never seen a bunny perform a blow job (the animal bunny), take it in the back door, or English mount another bunny, my characters will if the thought occurs to them for such a position.
Easy enough, yes? And yet there are still the publishing requirements. One publisher wanted sex within the first four pages. From Mavis meeting Marvin for the first time, to having his face buried in her p*ssy, there was to be immediate sex play. Once established, the idea was to keep it coming throughout the story. I believe the request is, quick, hot, often with a focus on sex and a plot directed at allowing sex to occur.
Another publisher requested (different than require but not by much) sex within the first 3k (12 pages). Much more do-able, if you'll forgive the pun. At least the characters can get beyond the handshake-jackmeoff moment and into, I'vejustmetyoulet'sfucknow moment. Breathing room.
Why do these publishers have requirements like this? Because it sells. With all the discussion around who has too much and who doesn't have enough and what does the reader really want to see, there is still that hidden question. Yes, we tell our stories and we give you the characters that you want to read about. But if you only wanted to read about the plot, most likely you wouldn't be book shopping in the erotic section (link). Or am I off-base?
There has been a strange twist in the market where the over abundance of gratuitous sex way overshadowing plot has reached an all time high. Readers are now saying that even erotic novels or short stories have too much. Where is the threshold? I believe we are currently seeking that line as authors and publishers.
So how much IS too much? Publishers push for more but have seen the downturn in sales. Readers want it but are disappointed in the level of plot development. Writers are frustrated, caught in the middle, wanting to give the readers what they want while reaching the demands of the industry standard.
I believe we need to write what fits. If Mavis and Marvin and nymphos, fine. Perhaps they are nymphos who meet in a hotel which has now caught fire and they are trapped on the top floor with the added twist that they must have sex on every floor to win a bet of some juvenile nature. Or perhaps Mavis is shy but a hot one and Marvin is the computer geek with whom she works. This character combo allows for a delay before intimacy begins. It would be out of character for Mavis to straddle him at his keyboard and go wild. Write what fits.
I believe that as long as the book isn't being forced and the characters made to act out of character, your reader will follow along with you, quite happy with the direction of plot and sex. But when it's forced and rushed... the reader will know it and knowing it creates discomfort. They will feel it in their gut that you, the writer, had it wrong. And potentially this wrong-ness could alienate them enough where they will be betrayed (see betraying your reader), possibly never coming back to you again.
If it's believable, write it. If it isn't believable, make it believable. It's your contract with your reader and is far more important than the contract you hold with your publisher. Change your story if you must, but do not betray your audience.