Want to test your relationship? Try travelling with your partner for a few years.

I had a scarf tied around my mouth to keep out the dust but I could barely get a lungful of air in the dank, sweltering atmosphere, 50 metres below the earth.

I was hunched over in the narrow tunnel, which had fallen in here and there where the timber supports had collapsed, every muscle aching and panic rising with every step deeper into the pitch-black cavern.

My boyfriend turned around to ensure I was still behind him and we locked eyes. I saw my terror mirrored in his eyes, which were all I could see of his face before his head-lamp temporarily blinded me.

He later told me that he’d turned to look at me for reassurance, maybe a thumbs up, but my eyes were so wide with alarm that he’d immediately thought better of it.

We were in a 500-year-old silver mine in the highest-altitude town in Bolivia, Potosi. The Spanish had funded much of their empire-building with its spoils and by the time Ed and I got there it was riddled with holes and had claimed xxxxxxx lives.

The day before we got there, two young miners had died when they hit a pocket of poisoned gas.

Yeah, we paid cash to risk our lives in a co-op mine where if you discover a seam of metal, it’s yours. Which means miners frequently dynamite straight into another miner’s turf. More deadly than awkward, really.

The worst part was when the miners set off a stick of dynamite in a cavern. The dull thud almost made my heart stop, then we all had to scramble over a single thin log that was suspended over what looked like an endless drop to get away from the dust that followed the blast.

Walking out of that mine towards the light I felt more intense relief than I have ever felt in my life, and I once sat through Tree of Life in the cinema.

It was just one of a whole load of uncomfortable, ill-advised, or downright dangerous things my boyfriend and I did during a six-month journey around Europe and South America en route to New York.

I’m not gonna lie, we fought.

We used to be one of those obnoxious couples that never argue about anything, ever. We really didn’t have a single fight in our first three years.

When we left the first house we rented together, a tiny workers cottage, our neighbour (who inevitably heard everything we ever said since we shared a wall) told us to keep being so kind to each other.

I’ll tell you what, though. Extreme physical discomfort and mental anguish (what am I doing, what the f*ck am I doing with my life?) will make you lash out, especially if there’s only one person who understands English nearby.

Sometimes, I wasn’t kind or understanding.

There was the time that we went to Montreal to get our US visas. Montreal is a lovely city and it’s easy to get around on Bixi bikes, like Sydney’s Citi Bikes.

Ed thought it’d be a great idea to go and pick up our freshly-stamped passports by pedal, and our AirBnB host assured us the that the ride out to Lachine was beautiful and would take about an hour and a half.

I coined a term that day. Crycling. It’s the action of cycling while crying hysterically.

It turned out there are two parts of Lachine: the lovely, waterside, bike-path bit, and the depressing, industrial part that’s a significant distance from the latter.

After going off-path (it ended) and riding along highways with trucks speeding past us, Ed said the words that made the throw the world’s most undignified tantie.

“Baby,” he said, after we’d been pedalling for about six hours straight, exhaustion and hopelessness etched on his face. “I don’t think we’re going to make it.”

We’d used the last of our money to book train tickets back to New York City and we due to depart at 9am the following morning. The post office opened at 10am and closed at 5pm. It was 4:50pm.

I pulled over, managed to haul my aching, wobbly legs off the bike and used my last dregs of strength to throw it onto the sidewalk while wailing unhelpfully about how this was all his fault and how we were probably going to die in Lachine.

We ended up rallying and pedalling for all we were worth until we arrived at a mail-sorting facility in the middle of an industrial estate. We arrived just as they were closing the doors.

It took about a year before that story was funny.

Then there was the time we accidentally adopted four enormous teenaged kittens in New York whose sole mission in life was to poop on everything we owned (not much). Ed called one of them Alex, because she ate all the other kittens’ food.

Or the time we moved into an apartment that we found on Craigslist in Harlem with a one-armed misogynist who tried to make us play Catan with him every night for three months and insisted he was an entrepreneur (if you can make a living watching The Sopranos on DVD, Ed would be a very wealthy man by now).

Or the time we got stranded on the side of a mountain in Peru in the rain after our bus-driver informed us the bus could no longer go up hills.

Or the time we both got explosive diarrhea in Argentina and couldn’t leave our hostel for two days. We got to know each other in ways we’d hoped we never would during those days.

Or the time Jeff Goldblum hit on me. He’s aged like a fine wine. It nearly tore us apart (call me, Jeff!).

The point is, travel can be bloody hard, and under duress and hardship, people’s real selves can be revealed – and sometimes they’re not pretty.

But if you manage to get through that? I think those experiences galvanised us. And showed us to each other at our worst. He still managed to love me even when I must’ve been an angsty cow.

And I still love him, despite, well, Lachine.