this is the rhythm of the night

Everybody that walks in that door becomes part of your problem. Anybody that comes in contact with you. I didn't want to be part of your problem, but I am. I'm leaving my husband, and maybe I would have anyway, but the fact is, is, I'm doing it now, and part of it's because of you. You've had an effect on my life.

Most people would give anything to be turned into anything else, because most sex is mediocre, and the measure of its mediocrity is that it leaves us unaffected. No one falls ill; no one transforms into a fly or a cockroach; nothing changes. As the narrator of Norman Rush’s novel “Mating” sagely observes, “Sex can be various things, but in my experience the usual thing it is is considerate work on the part of both parties,” accompanied by the exchange of careful courtesies: “after you, no, after you, mais non.” No one has transformative sex all the time, and there is nothing wrong with sex that is merely pleasant. Indeed, a polite volley of pleasantries is probably the best thing that unecstatic sex can be.

Of course, many mediocre sexual encounters are rote in a more pernicious way. Heterosexual sex that follows the standard scripts, with its spankings and its schoolgirls, is not always devastating or traumatic, but its tiresomeness is nonetheless not innocuous. Women are the most obvious losers when the scenarios faithfully reënacted in the bedroom so consistently favor male predilections, but men who inherit their desires from the prevailing sexual culture—or, worse, men who feel they must satisfy a virile masculine ideal whether it appeals or not—lack the opportunity or the means to develop sexual agency. For both parties, the resultant comedy of errors is not satisfying. What nefariously underwhelming sex has in common with respectfully underwhelming sex is that neither brand is especially surprising or especially erotic.

To have sex erotically—and ethically—is to have it with someone else, and a person demonstrates her difference from the self by being impossible to predict, domesticate, or assimilate to preëxistent fantasy. It is not erotic to impose a ready-made desire onto someone pliant, or to slot her into a fetish that has little to do with her. Eroticism occurs only when someone rewrites us so completely that she rewrites even the quality and content of our appetites, and only when this radical rewriting is reciprocal.

Eroticism does not arise every time there is sexual activity, no matter how plodding, but it is also not the exclusive concomitant of love, marriage, or conventional commitment. Most sexual pairings are no more dishevelling than a game of tennis, but it is constitutive of sex that it has the potential to thrust us into metamorphosis that may be sweet, may be sinister, and may be both concurrently. When at last we grow wings, who can say exactly where we will want to fly?

Can a person consent to dying? Can she consent to a complete renewal, which amounts to the same thing?

Surely she cannot consent in the normal way. To consent in the normal way is not merely to grant permission but to grant permission on a particular basis—perhaps a reasonable expectation of pleasure, security, or safety. In any case, there is some positive inner state to which the outward utterance of license is supposed to correspond. A woman, almost always the presumed consenter in a heterosexual exchange, is exhorted to have sex with someone only when she has good reason to believe that she will have a generally happy time with him. Over and over, she is told: you don’t have to do anything you don’t want to do; you don’t have to do anything that makes you uncomfortable. Because she is assumed to know exactly what makes her comfortable, and because comfort is assumed to be a necessary condition of good sex, the procedure the consenter is instructed to follow is not unlike the operation favored by decision theorists. First, she is to imagine what sex with the partner under consideration will be like; second, she is to assign a value to the experience that she has conjured; third, she is to assign a probability of accuracy to her prediction. Having done all this, she finds herself in a position to make a rational decision, consenting if and only if she foresees that an exchange will turn out to be unimpeachably agreeable. Should she prove wrong in her predictions, should she ever feel the slightest scintilla of unease, she should withdraw her consent and beat a hasty retreat.

Three faulty assumptions are baked into this model. The first is that people in general, thus women in particular, can predict, if roughly, what a prospective partner will be like during sex; the second is that people in general, thus women in particular, can predict what they will be like during sex with a prospective partner; the third is that sex can and should be comfortable.

In fact, we are not impermeable packages of preformed desires, importing our likes and dislikes around with us from one encounter to the next like papers in a briefcase. An erotic craving is inextricable from the ferment that foams up when oneself is sluiced into another. Not only is it impossible for us to know whether an encounter will be deflating or transformative but we cannot know what sort of metamorphosis will ensue if the sex is as jarring as we can only hope it will be. We can have no more success when it comes to divining how we will change our partners than we can have when it comes to divining how they will change us—or, following Cummings, how their changes will change us, and how our changes will change them, iteratively and indefinitely. Maybe we will grow the wings of cherubs, but maybe we will find ourselves meshed with the coarse bristles of gigantic flies. All we can say with certainty is that sometimes, when it is working, sex carves out new bodies for our bodies, and these bodies can be both better and more brutal than the ones we could invent alone.