MY HUSBAND GOT to celebrate turning 37 by spending three nights on an inflatable mattress on a friend’s living room floor in Copenhagen. The lucky devil. He may have thought his floor-crashing days were behind him, what with the fact that he’s knocking on 40 now. Not so.

I like to point the finger at budget airlines, which have made it possible for us to travel to places where we can’t afford accommodation once we arrive. The upside is that, in the meantime, we’ve been honing the art of houseguestery.

We are of that particular, spare-roomless generation forced by inflated property prices to live in undersized, overpriced housing long, long into our adult years. Yet we’ve travelled far more than our parents ever did. The combination of these two factors means floor crashing and couch surfing is likely to last well into our dotage.

This is all compounded by the fact that I am inexplicably compelled to tell every stranger encountered in hostels or bars across the world that mi casa es su casa, should they ever pass through Dublin. As an ambassador for Irish hospitality, one feels duty-bound to extend such offers to those of a foreign persuasion. They’re not supposed to take you up on it.

But it turns out other cultures are much more direct than ours; they say what they mean and assume we do the same. Bah! Thus it has come to pass on more than one occasion that a random Australian turns up on the doorstep clutching a beer mat with my address on it. Out comes the spare duvet again.

As a result, you get well used to having houseguests, and fairly adept at handling the encroachment on your living space, or waking up to the sight of some vaguely familiar-looking French chap doing yoga on your kitchen floor.

The standard of service supplied, however, has become directly proportional to the level of friendship: if you’re a hostel randomer I haven’t seen since the Bolivian salt plains tour, you get a house key and a map of Dublin. If you’re one of my beloved and bosomest buddies, you get a personalised city tour, a full Irish breakfast in the morning, and maybe even the use of my fancy bath products.

It is my fervent hope that such experiences as hosts have at least made us better houseguests. After all, we have learned (through bitter experience) not to use up all the loo roll, to tidy the bed clothes away every morning, to wash the tea and coffee cups after ourselves, to navigate new neighbourhoods without expecting our hosts to hold our hands, and crucially – take note, any of you still in possession of one of those scrawled-upon beer mats – to arrive bearing gifts.

We also know to appreciate our free accommodation, regardless of the condition in which we find it. So yes, there may be a slight sag at the smile corners when our hosts point out that, not only is their toilet halfway down the backstairs of their building, and unheated in this Scandinavian wintertime, but that it is so cold there that the water in the cistern has frozen.

This means not only that all, er, movements, have to take place in temperatures below zero, but that each one requires a bucket of water carted down from the kitchen to make it all disappear.

But we do not let our chagrin show. We cart our tell-tale buckets up and down the freezing back stairs without a whimper, we dress gamely behind the couch, we take two-minute showers every other day (due to hot water rationing) and, as difficult as it may be to believe, we have a hoot of a holiday.

Maybe it’s because we get the bosomest buddy tour, complete with the full Danish breakfast (less deep fried, more cheeses) and menu translation services. Or maybe it’s because, while mini bars and water pressure are all very well and good, there’s a lot to be said for waking up on a good friend’s floor to drink tea out of her teacups, read her bathroom magazines and borrow her clothes. Especially when it’s the kind of friend who is so close that her casa really does become your casa.

In fact, such was the level of comfort and sense of at-homeliness to be found therein that my husband even took to dusting their mantelpieces in his afternoon downtime. You’d never find him at that in the Four Seasons.

I’m not sure it’s the kind of hospitality my parents’ generation would expect, or even put up with. But the benefits of music festivals and grotty bedsits are clearly finally paying off, as a whole new generation can now put a full face of make-up on with only a side mirror and a street lamp to hand, and get undressed and into bed in front of a room full of people without ever appearing to take off their clothes.

It’s the kind of adaptability that ensures slumming it just ain’t what it used to be, and makes falling asleep on somebody’s floor as easy as on a high-thread-count hotel bed.

Which considerably helps with the budget birthday treats. In fact, our weekend on a Danish floor went down so well, I could detect more than a modicum of disappointment in the birthday boy on his return to our own electric shower and flushing toilet. It was all I could do to get him to sleep in a proper bed again.

It’s certainly going to be hard to top when the next birthday rolls around. I’d better start digging through the beer mats.