On any given day, many millions of people worldwide will be secretly turning the issue over in their minds as they go about their daily lives.

Their partners beside them, possibly having little clue as to the momentous decision weighing upon them.

The choice is perhaps more common now than it ever was.

We expect to be deeply happy in love, and, therefore, spend a good deal of time wondering whether our relationships are essentially normal in their sexual and psychological frustrations,

or are beset by unusually pathological patterns which will impel us to get out as soon as we can.

What films or novels we've been exposed to, the state of our friends' relationships, the degree of noise surrounding new sexually-driven dating apps,

not to mention how much sleep we've had can all play humblingly large roles in influencing us one way or another.

Awkwardly, it seems that no one else actually really minds what we end up doing, which gives the decision a degree of existential loneliness it might not always have possessed.

Historically, the choice was, in a sense, a good deal easier because there were simply so many stern external sanctions around not leaving:

religions would insist that God blessed unions and would be furious that they're being torn asunder,

society strongly disapproved of breakups and cast separating parties into decades of ignominy and shame.

And psychologists would explain that children would be deeply and permanently scarred by any termination in their parents' relationship.

But, one by one, these objections to quitting have fallen away;

religions no longer terrify us into staying, society doesn't care, and psychologists now routinely tell us that children would prefer a broken family to an unhappy one.

The burden of choice therefore falls squarely on us.

The only thing determining whether to stay or leave is how we feel, which can be a pretty hard matter indeed to work out for ourselves,

Our feelings having a dispirited habit of shifting and evading any efforts of rational qualification.

In the circumstances, it might help to have a set of questions, devil's advocate in nature, to fall back upon —

a kind of checklist to dialogue within one's mind, in the silent hours of the morning, from the chill vantage point of the spare room couch.

How much of our unhappiness can be tightly attributed to this particular partner.

And how much might it, as we would risk discovering five years and multiple upheavals later,

turn out to be simply an inherent feature of any attempt to live in close proximity to another human.

Though it is, of course, always essentially their fault, what tiny proportion of the difficulties might we, nevertheless, be contributing to the discord?

In what modest way might we be a little hard to be around?

Consider the annoying traits in all previous partners we've had and people we've known that our current partners happen not to have,

what do we manage not to fight about?

Start to probe at any new infatuations or crushes, largely by getting to know them better.

Observe closely how many sexually available and intelligent people the single types around us, especially those hooked up to those new dating apps, actually manage to encounter day-to-day.

Try to have another conversation with your partner in which you don't accuse them of mendacity,

and instead simply explain, quite calmly, how you actually feel and how sad you are about quite a few things.

Reflect on how you'd really feel as a child, if henceforth, you were to have two tiny bedrooms, two new step-parents, and possibly a few more new half-siblings,

compare with the scratchy reality of the current setup.

Question how normal it is for any couple to have great sex after twenty-two months.

Ask yourself if you're ready to face the risk of perhaps achieving no more than exchanging a familiar kind of unhappiness for a new and more complex variety of unhappiness.

Wonder whether you really want to choose hope over experience.

Then, if you still have the impulse to leave, with chances of subsequent regret lessened to at least a touch, with a heavy heart, and a cautious mind, leave.