My best friend and I share the same ex-husband. We call ourselves ex-wives-in-law.

When my best friend Shelley and I are out together, people often ask if we are sisters, even though we look nothing alike.

Shelley has dark hair, dark eyes, and very fair skin, and while I also have fair skin, I’m a blue-eyed blonde.

We get the question so frequently that it’s almost comedic. “No,” we tell whoever is asking, “we’re ex-wives-in-law.” This always gets a laugh, and when we explain our story, it brings a moment of levity to whomever we’ve encountered.

Behind what we’ve made into a little joke for public consumption is a unique bond that a lot of people wouldn’t understand.

It’s a bond forged by trials, reinforced by implicit trust and devotion, and topped off with a whole lot of laughter and joy. “Our Husband,” as we call him, was intent on Shelley and me getting to know each other before they married.

He and I have two sons, and Shelley has two sons from a previous marriage who are about the same age as my boys.

This meant that we had many of the same interests as boy moms by default, but, as it turned out, we also shared many of the same tastes in music, art, and books.

One milestone event of my life occurred early in Shelley’s marriage to Our Husband.

Shelley and I went to see Prince in concert together shortly before his death.

I will never forget that night, and I’m so thankful that I got to see him perform live.

In retrospect, I could see the spark of our friendship starting to glow that night.

Strangely enough, though, the night that I count as the true beginning of our friendship was the night that the Diane Sawyer interview featuring Caitlyn Jenner aired.

For me, this was one of those events in the cultural zeitgeist that seemed like it should be witnessed with someone else.

As it happened, all four of our boys were on the swim team together, and the program aired on the night of a meet.

Our Husband was working that evening, and I told her I’d be over with food to cook dinner for all of us.

I came to her house — the house that she shared with Our Husband, who was my ex, of course — and we made dinner for ourselves and the boys, drank some wine, and watched the interview.

Shelley told me much later that she initially thought it was weird that, as Our Husband’s ex-wife, I was so intent on being her friend.

She says her mother told her, “I think you might as well give in, I think she has decided you are friends.” The truth is, I just plain liked her, and we had a lot in common, but her mom was right.

Sadly, Shelley’s marriage to Our Husband ended after four years.

She has said that I put her back together after that all happened.

She emerged after that crisis like a butterfly coming out of its cocoon, and our friendship grew, battle-hardened, to a new level.

Through all this, we shared parenting crises and triumphs, career battles and successes, and personal health scares.

Then, together, we went through something foundationally shattering for both of us.

We both cared for our aging mothers, and connected even more deeply after they both died.

For a daughter, losing a mother is a life-changing event.

On top of that, being a family caregiver, being involved in the deeply draining day-to-day process of shepherding a loved one toward and through their transition in death, is a solemn responsibility, the parameters of which are indescribable to anyone who hasn’t experienced it.

As it happened, just by circumstance, Shelley walked those paths ahead of me and alongside me, and we held each other together through tears and laughter along the way.

Shelley’s mother died on March 18, 2019.

My mother died on March 16, three years later.

Shortly after she passed, Shelley, Our Husband, and I sat in my living room and toasted her with a round of her favorite drink, gin and tonics, in recognition of the valiant battle she had just completed.

So how does Our Husband feel about Shelley and I being so close?

For him, it’s been kind of like the five stages of grief.

First, he tried to deny that we were actually friends.

Surely, we were just pretending to be friends — certainly, this was just a charade, we were just doing this to spite him.

Apparently, we were friends, which just wasn’t appropriate in his view.

If we’d stop seeing each other, he’d be nicer.

Yes, Shelley and I were friends, and that just sucked.

Sometimes, he refers to her as my “girlfriend.” Of course, a lot of time has passed, and I like to think that all three of us have grown a great deal.

Shelley and Our Husband have been divorced for 10 years.

My relationship with Our Husband has gone through many evolutions.

He and I have been divorced for 14 years and apart for 17.

Above all else, he gave me the greatest gift one human being can ever give another in making me a mother, and we have two wonderful sons who are young men now, out in society, being productive citizens.

Little did he know he’d also give me another wonderful gift when he got divorced for a second time.

He gave me my best friend for life, my person.