We held tightly to each other, crying as we said goodbye. It had been a passionate three years, but we'd reached an impasse: I wanted a child and he didn't.
Our friends assured us we'd made the right decision.
"What a Peter Pan. Thirty-five years old and just wants to play. Grow up or get out," mine quipped.
"Dude, you live for adventure. You're not the 'white picket fence' type. If you stayed, you'd have resented her," his reasoned.
Six months later, I doubted our decision to break up. I was 33 and Tree was the only boyfriend with whom I'd ever envisioned a future. Who knew if I'd connect with another person and, if I did, would I be too old to have kids? Even worse, I realised a large part of my desire to have a child was tied to the passion I felt specifically for him.
I'd made a huge mistake.
The telephone rang. Climbing in Yosemite, surfing in Costa Rica - they'd lost their appeal without me, he said. He made a big mistake too.
We hadn't resolved our deal-breaker. But through the agony of still being in love, we'd each become less sure about "the kid thing" and very sure of our need to be together.
As we had no clue how to compromise - you either have a baby or don't - we decided not to talk about the future. Instead, we busied ourselves with wine picnics.
Then, the Great Recession arrived. I lost my job as a sales consultant in Los Angeles and Tree, who owned an online adventure store, was facing a serious cash crunch. We couldn't afford rent, let alone a baby.
Given our grim finances, he suggested that we do something different.
"Let's take a long road trip," he said. "To the tip of South America. We'll drive the Pan-American Highway for one year to the end of the world."
"How will we afford that?" I asked.
"We'll live in the van. It has everything - a kitchen and a bed. It'll be like camping, but intense."
As cramped and foolhardy as the idea sounded, I agreed to go, reasoning this could be our last hurrah before settling down.
Two weeks later, we moved into his converted Sprinter to start #vanlife, years before the hashtag existed.
As we headed south, our lives changed dramatically. California high-rises and suburban sprawl gave way to dusty pueblos and small fishing ports. We went from spending weekends together to never leaving each other's side.
Gone were the nights of expensive wine bars and Netflix. Now, we visited ancient ruins in Mexico, surfed secluded breaks in El Salvador (where we eloped), climbed volcanoes in Nicaragua, jumped off waterfalls in Honduras and were prepping to paraglide off the Andes.
Well, I was prepping - mentally. For Tree, extreme-sport adventures were like spiritual quests. Big-wall climbing, white-water kayaking - these were ways for him to "touch the void" and if he could share this connection with me? Even better.
For me, though, deciding whether to leap off a mountain felt like doing maths with a gun to my head. Calculate risk correctly or die.
One night, as we were sitting around the campfire with a fellow traveller, the conversation turned to children: Were we going to have any? Before I could give our pat answer, Tree said "definitely".
I did my best not to squeal aloud while he explained that, while we were bummed about it, we'd have to hurry through the rest of South America. We'd already been travelling for more than a year; the clock was ticking.
"But why do you have to go home? Babies are born all over the world," our friend asked.
Later, lying in bed, I asked Tree if he was sure.
"Yes. It'll be the greatest adventure of my life and I get to share it with you," he said. That night, we both decided to take the leap.
A year later, we found ourselves still living in our van, by then in Peru, with a newborn baby girl in our arms. We named her Soleil, which means "sun" in French.
Soon after, we bolted a car seat to the floor of the Sprinter and continued our journey through Bolivia, Argentina, Chile and Brazil for another two years.
As the countries accrued, however, every inch of space in the van filled with toddler gear - a travel crib, books, dozens of outfits and tiny single socks (their matches strewn across Latin America). Finally, we had to admit we'd outgrown our home. Long driving days and constantly moving also became a struggle. Our lifestyle wasn't working anymore.
So we changed it.
Now, we slow-travel - meaning we stay put for a while, enmeshing ourselves in the community. Our belongings fit in a minivan, but we stay in small, furnished apartments for months at a time, road-tripping and hostel-hopping between longer-term destinations.
For example, last November, we became legal residents of Spain and our daughter attends a local pre-school. Our life is replete with paediatrician appointments, play dates and birthday parties.
In December, our family flew over from the United States and we spent Christmas with Soleil's grandmother, aunt, uncle and cousins.
In May, however, we'll hit the road and I'll go back to home- schooling Soleil. Our good friend, whom we met in Argentina, will join us as we travel through Morocco, Portugal and France, where we'll stay in hostels and meet other nomadic families.
Then, we'll spend six weeks in the US visiting relatives before heading back to Spain in September.
The Internet is what makes our adventure-driven life possible. We're able to stay in contact with friends and family, meet other travellers and coordinate details such as visa renewals and global health insurance. Most important, it allows us to work remotely to finance our downsized, on-the-go lifestyle while still saving for college and retirement.
Sure, we have new things to consider: Is the destination kid-friendly? Did we pack a blanket for nap time? But nothing is more rewarding than living our passion together.
Our daughter is now four, speaks Spanish and English, is learning French and loves theatre, art, climbing and swinging into space from an overhung rope.
Will we do this forever? Who knows, but as our daughter continues to grow, and Tree and I get older, our lifestyle will surely adapt again - and it will be a whole new family adventure.