The hole truth

You need to be quite adult about this - we need to have a talk about some of the human orifices.   They have an impact or your readers' sexual drive, and thereby could impact your writing.   And it is not impossible you might get to understand yourself a little better.

There are over 60 types of sphincter, or anus, in the human body but only one that we can readily identify:  to such an extant that the word anus has, for the vast majority of us, become to mean that one.   The one that everyone has, but very few ever get around to talking about.   The possession of an anus seems to be a bigger secret than having a spanking element to one's psyche.   By far, the item most often stolen by shop lifters are hemorrhoid treatments - because being caught stealing is far less shameful than letting a store clerk of an embarrassing medical condition.

At the other extreme, some people get a great deal of innocent pleasure from wearing "butt-plugs" - a sort of dildo that is inserted into the anus and left there for a while.

Which makes the topic of anuses a tad tricky for us writers of spanking fiction.    The slaps are being delivered in close proximity to an anus - in some forms of extreme BDSM to the actual anus itself - and as writers we can narrate about it or turn a blind eye to it.   Which is more correct?   It depends.

There are three words that are perfectly permissible in "polite" fiction:  penis, vagina and anus.   Provided that very few adjectives are added to any of those three nouns:   too many adjectives and the line has been crossed taking our work outside that which is considered polite.   And if you use any of the common crude terms instead of the scientific nomenclature, you have instantly become "impolite".    Indeed, lots of adjectives with crude terms and you meet one of the more common definitions of pornography.

Writing pornography is perfectly OK - provided that you do not try to sell it to people having disguised and promoted it as polite fiction.   That would be some sort of breach of trust in the unwritten contract between author and reader.

If your target audience is one that expects you stay within the confines of polite society, then mentioning the existence of the anus between the buttocks should only occur if, for some reason, it is germane to the story.   And even then, only a passing reference.   If you are writing to those who enjoy pornography, describing in meticulous detail the spankee's anus and what happens to it during the course of your tale is not only warranted, omitting it would - for some readers - be something of a let down.   Your readers,  your writing.

That is enough on this topic for today.   It might interest you to know why the anus is part of the sex drive, and that is a topic I shall return to in the near future.