People—and by extension, characters—regularly do things that they don’t mention, or even admit to, even though they aren’t illegal, immoral or physically harmful. Writers can make their characters more realistic when said characters engage in unmentionable behaviors. What follows is an extensive but not exhaustive list of possibilities.
Nose Picking is a prime example of a virtually universal unmentionable behavior. It has its own Wikipedia entry, complete with a technical definition (extracting nasal mucus with one’s finger) and formal label of rhinotillexis. Psychiatrists at the Dean Foundation for Health, Research, and Education in Wisconsin conducted a study revealing that 91% of people said they were currently nose pickers (though only 75% believed everyone did it).
So, how and where does your character nose pick? Always the same digit? Always the same place? Always the same time of day?
And then what? Is the residue flicked off? Wiped on a tissue? Wiped on the underside of an article of clothing? Wiped off on a rug? On furniture? Added to a booger wall? Or maybe the residue is eaten.
Mucophagy is the technical term for eating nose pickings. Most societies condemn it, but some scientists claim there are health benefits. Dr. Friedrich Bischinger, a leading Austrian lung specialist, says that eating one’s mucus gives “a natural boost to their immune system” because the mucus contains a “cocktail of antiseptic enzymes that kill or weaken bacteria that become entangled in it.” Reintroducing weakened bacteria may allow the immune system to safely produce antibodies.
Time considerations for nose picking. How often? A few times a day—however unmentionable—isn’t odd. But one-to-two hours daily? When it becomes an obsessive-compulsive disorder, it’s called Rhinotillexomania.
Wiping your nose on anything available.
Urination is another universal. How about peeing in the shower? Or the bathtub? The ocean—or the swimming pool? Is your female character comfortable urinating outside?
Recently, there have been a number of devices developed and put on the market to allow women the same ease of urination as men. They come in very handy on long car trips or when getting to the bathroom requires a trek through an unheated house, up a snowy mountain, and behind a tree to squat over an unsettlingly drafty hole in the ground.
I once spent two weeks on a whitewater rafting drip on the Colorado River. People were required to pee in the river. (Recall that urine is sterile.) In camp men simply walked to the edge of the water. Women often waded out and pulled down their pants. On the water, men stood at the stern. Women pulled down their clothes, hung onto the cargo straps, and cantilevered out over the water.
In all of these circumstances, the other people politely looked the other way. But then how did it happen that the last night out I was voted the person most improved in peeing off the side of the raft? So if your character is urinating in unmentionable ways, consider both culture and circumstances.
Defecation is always fertile ground. It seems whole herds of people get completely naked to poop—every time. Imagine trying to use a public toilet!
Consider a character who wipes his/her anus and looks at it. Or smells his/her fingers afterward. One justification for frequently smelling one’s anus or genitals (via finger swipes) is being familiar with one’s usual smell so that changes that might signal a change in health status would be recognizable.
Not washing hands after using the bathroom. Or even turning on water so others in the public toilet will think you washed when you didn’t. And it raises the question of why not wash?
Burping, a cousin to the more offensive Passing Gas. These things happen.
I remember a joke from grade school. “What did the stomach say to the burp?” “Be quiet, and I’ll let you out the back door.”
But what about someone who burps and/or farts on purpose, on demand, or as loudly as possible?
What about someone who intentionally farts in elevators, subway cars, on trains or busses and casts a blaming glare at those nearby?
What about intentionally expelling loud farts and/or burps but only when alone?
Or sniffing farts to try to figure out which food made it smell that way.
For truly obnoxious characters (and spouses), there is the dreaded Dutch Oven: farting in bed and then pulling the blanket over your bed partner’s head, trapping them in the stench.
And consider whether your character has an extreme reaction to other people’s flatulence. I know of a woman who became furious if someone passed gas in her presence: smell is a molecular sense, so smelling a fart means taking in fecal molecules.
Eating is fraught with unmentionable behaviors. For example, eating food off the floor after 5 seconds have passed.
Eating from the cooking pot. Eating/drinking directly from thecontainer. (In this case, whether your character lives alone is relevant. )
Eating food other than snacks or sandwiches (for example, tossed salad) with fingers. Eating the unthinkable as a regular thing: chalk, insects, dirt, tissue paper, etc.
Nakedness is sometimes necessary, of course. But what if your naked character regularly sits on the sofa and reads? Cooks dinner? Sits on the deck or patio—and if so, at what time, and how private is the space?
What about taking naked selfies for no particular reason? Saying you deleted the naked pictures sent to you but you didn’t?
Sucking Blood From a Cut.
Having sexual thoughts about an inappropriate target. Think relative, someone else’s spouse or partner, subordinate—whoever is beyond the pale because of relationship or other taboo.
Self Absorption.is almost always unmentionable! Narrating thoughts aloud—while driving, planning, etc. Closely related to talking to oneself.
Consider cracking up at one’s own jokes, even when alone. Practicing pick-up lines in the mirror, ditto facial expressions. How about making weird faces at yourself? Or googling oneself?
Women Only Unmentionables.Shaving—where and how often. Plucking or shaving facial hair from eyebrows to chin and jowls. Obsessing about changes in body odor during menstruation. Collecting “fuck me” shoes in colors to match every outfit.
Men Only Unmentionables: measuring his dick, jerking off to fantasies of his friend’s girlfriend, windmilling/ helicoptering his penis, frequently resettling his junk in his banana hammock.
Miscellaneous unmentionables could be almost anything.
Dancing like no one with the authority to commit you is watching
Running up the stairs on all fours
Eavesdropping or otherwise spying on people—including reading another person’s mail, email, or texts
Squeezing pimples or blackheads
Climbing on furniture
Bouncing on the bed
Making weird noises
Breath syncing to someone else, music, in the extreme known as sensorimotor obsession
Arithmomania, a strong need to have one’s life governed by odd, even, or certain numbers, brushing teeth to setting the thermostat, etc.
Blow-drying “down there”
Overview for writers: Make your character more human by giving her/him a characteristic unmentionable behavior or two. Don’t go overboard unless your character is totally neurotic and/ or you are going for humor. And remember that such behaviors are even more revealing if the characters do such things in the presence of others. Have fun!