Wearing a thong under his Manchester United togs may put spice in David Beckham's romance but for most marriages these days, you don't need tight underwear to sense how partnerships pinch. Whether power marriage or good old quest for intimacy, play truth or dare with most married couples and the answer to "What's it like?" must be "Ouch, it's tough."
Quests for intimacy become passionate struggles to find some sort of personal space. Within months of the ceremonial act, you realise that what you used to call "compromise" is about as close to its real meaning as ice cream is to snow. With women's financial dependency on men quickly disappearing and equally speedy alterations in relative earning power, a quick look at the institution makes you wonder whether and how it will survive.
Marriage made some sense when economics governed its transactions: no sex, no children and no full social respectability unless you tied the knot - in theory at least. Not now.
Marriage is losing its appeal as a primary rite of passage, despite more people worldwide opting to marry a succession of partners in greater numbers than ever before.
Even apart from the ceremonies, nearly 25 per cent of babies in the State are born to single parents.
Half-brothers or sisters, multiple biological and cultural grandparents, even a civilised relationship with a husband-in-law (your husband's ex-wife's current husband: she becomes your wife-in-law) can't mask the trend that is splicing the concept of marriage from that of family for the first time.
Some folk say that because social and family cultures are changing, people who are, or are about to be, married expect too much. This, they argue, explains the contemporary partnership pinch.
No doubt it's plain silly to expect consistent romance, excitement, or that your partner will be able to read your mind at times when you don't even know what's on it.
Communities that honestly want to help people's marriages aren't likely to achieve that outcome by putting the institution first. If coercion may have kept marriage going for longer than some should have, helping contemporary marriage means facing the human consequences of promoting a cash-rich, time-poor culture alone.
The longings for intimacy and companionship that mark contemporary marriages are neither new nor selfish, despite some claims. Human hope may be more art than science, but it's trucked along through centuries of change.
Look at history and you confirm what you may have suspected all along: that people always hoped for such qualities, and at their best survived the gradual dulling of pheromones by amplifying the full resonance of that old thing called love.
Art Ui Laoghaire's widow became a poet after he died, and not only because she had to raise their children alone. Whether you take advice from the Wyf of Bath or your best friend's father, a good marriage may well be a triumph of will over feeling, or indeed of feeling over sense.
Like most indications of mental health, we could be happier letting some illusions reign. Marriage has few empirical measures. A minority of married people do live the hell on earth of a persistently emotionally or physically abusive partner, in which case it's time to take serious action. But for the rest, there is no reliable map.
The happiest marriages people admit to are those which are childless and relatively financially comfortable. Men tend to report higher contentment levels than women.
But whatever your happiness rating, the ball game changes drastically once a child or children comes along.
You know at the pivotal moment when the promise of an early night finally starts to mean getting some sleep that Nora Ephron's branding of a baby's effects as "a grenade thrown into a marriage" wasn't just a clever phrase. Even new men and new women may suddenly find themselves rehearsing old moves.
Irish people are quite sensibly voting with their feet, or more accurately, their left-hand ring fingers. People here can afford to marry earlier than ever before, yet they are not. Good for them, some will say.
Marriage was tough enough when you broke both legal and tribal values if you dared to step outside it.
But in this cash-rich, time-poor age, once the wedding dress is packed in mothballs and the morning suit returned to the rental shop, its dynamics are seriously up for grabs.
No matter what the culture pretends, marriage is not a natural state. Swans do mate for life; humans have to work at it. You know this before you marry, but the full resonance hits you later - and keeps on doing so until death does you part.
Whatever advice you're given, or whatever training you try to access, the lived experience is so far from the theory that at times you'd need a personal coach just to get you through. Marriage manuals try their best, but might more accurately bear titles like The Shock of the New.
Centuries of experience about how men and women live in harmony together come to naught the day after each couple stands in front of a registrar or a clergyman to take their solemn vows. Like falling in love, each pair who live it do so as if for the first time.
Unmarried people seem to know this instinctively - and question married couples as if they are curators of some mysterious futuristic museum.
Stay married for 10 years and people congratulate your endurance. Stay married for 20 or more and younger folk may regard you as a quaint, if puzzling, fogey.
At the end of it all is an image, perhaps a fantasy, of lasting love where a man and woman sit hand-in-hand as contented senior citizens, having finally worked it all out.
Endurance, enjoyment, companionship - the question is how we manage all that in between.
e-mail: mruane@irish-times.ie