PARIS • A few years ago, my husband and I went to a restaurant on a Friday night.
The Aperol spritzes had just arrived - we lived in Geneva, where the language is French and the cocktails are Italian - when a man I didn't know approached our table.
He started talking. My husband chatted back.
On the sidelines, I limbered up my bonsoirs and enchantees. But I never got the call-up. The man walked off and I remained an unidentified sitting object - mute, anonymous, peeved.
"Why didn't you introduce me?" I asked my husband.
"Why would I?" he replied. "That wouldn't be normal. I barely know him."
My husband, I had to remind myself, is a courteous person. He is not a misogynist, a narcissist, a bigamist or any other agent noun that would predispose him to freezing his wife out of a conversation.
As far as our prospects for cultural misunderstanding go, however, it's worse than that: He's French.
I never would have guessed I'd become one of the more than four million Americans married to a foreigner when we met, six years ago, at a party in London.
That was awkward too.
I thrust out my hand, saying, "Hi, I'm Lauren." I would learn, much later, that French people have their own set of rules for making introductions. At social events in Paris, where we now live, kisses are exchanged before names.
In the small, proudly uncosmopolitan town in North Carolina where I grew up, the definition of exogamy was marrying someone from New Jersey. Our family trees grew in neat orchards of demographic similitude.
Our parents, like their parents - the odd war bride aside - had paired off with people who were their mirror images.
This was a function of time as much as place. There was no Internet. There was no weekend in Reykjavik.
The United States Census Bureau began to take note of "mixed nativity" marriages only in 2013. But for the past four decades, multicultural marriages - interracial, interethnic and interreligious - have been increasing, with at least 7 per cent of married-couple households now including one native and one foreign-born spouse.
In California, Nevada, Hawaii and the District of Columbia, the rate is about double that.
This is not just a US phenomenon. In 25 out of 30 European countries, for example, mixed-nativity marriage is on the rise, with the proportion, in some cases, reaching up to 20 per cent.
Studies have suggested that multicultural marriages are a tricky undertaking, with higher rates of divorce.
There are psychotherapists who specialise in multicultural couples counselling. I imagine that they must occasionally zone out during the telling of yet another tale of mistranslation, homesickness, conflicting traditions, fuzzy communication or visa woes.
Trouble lurks in the quotidian in multicultural partnerships. Trying to decide on the appropriate hour for dinner - in France, 9pm is par - has caused more drama in our household than the more universal stumbling blocks of what to name our daughter and where to live.
There are certain pleasures we'll never share, such as eating cold pizza for breakfast.
But for every ease that multicultural marriage takes away it offers an enrichment. Authentic recipes (hint: throw a "couenne de lard" - raw pork rind - in that "daube de boeuf"), spare passports, children who can bounce between two languages without ever once having drilled themselves on first-group verbs.
There's freedom in carving out your own way of doing things.
You have to think hard about your priorities when you can't simply default to a shared norm. For me, learning French has been a profound gift; just being able to read the news in another language is like discovering that your house has an extra room you never knew existed.
When you make a family with someone from another country, you get double the music, double the movies, double the teams to pull for, double the holidays. You travel. Your parents travel.
"It is prone to problems, but the chances for a rewarding relationship are better than average," the authors of a Finnish report on binational marriage concluded.
This rings true to me.
Anyone who risks a life with someone outside of his in-group - not only across lines of nationality, but also those of religion, race and class - becomes a participant, whether he knows it or not, in a global experiment in developing empathy.
The awareness and negotiation of small differences add up to a larger understanding about the complexities of the world.
The day that my husband and I marched alongside more than three million of his countrymen in the wake of the Charlie Hebdo attacks, I understood, in my bones why a "rassemblement" isn't exactly a rally or a protest, that the flag doesn't signal the same thing to the French as it does to Americans, and that each society has its ways of expressing patriotism, belonging and grief.
I've tried to remember this recently as my husband and I have butted heads over the meaning of the burkini.
I'm thankful that we're forced to. It's far more difficult to dismiss difference when it's sitting across the dinner table - even if it occasionally neglects to introduce you.
•Lauren Collins, a staff writer at The New Yorker, is the author of When In French: Love In A Second Language ($22.40, from www.amazon.com).