I was once dating an openly married man who had never, in the six years he'd been with his wife, been monogamous. (We'll call him Kevin.)

Even at the start their romance, Kevin and his wife had been open. They seemed happy and stable, and he often gushed about how amazing she was (she was pretty damn amazing).

Then suddenly, for the first time since he met his wife, Kevin fell in love.

"She might be done with me," he texted me after he told her.

"Drop me, Kevin. Win her back," I replied.

I believe Kevin and his wife are still together. I believe they are still open. Kevin and I, as you might suppose, are no longer in contact.

The Problem Wasn't That They Slept with Other People

It was that they had no plan for what to do if one of them fell in love.

You can't make falling in love "off limits," because over a long enough timeline, it will happen.

In the same way that monogamously married partners will still get crushes on people from time to time, people in open marriages do too — but in an open marriage you get to explore those crushes, which can then grow into full-fledged love affairs.

If you are in or considering an open marriage, you need to consider the very real possibility that one or both of you is going to fall in love with someone else.

And when that happens, what will you do about it?

If you decide that the plan is to end the extramarital affair if love enters the mix, you are signing up for a very great challenge — one that will be even more challenging for the kind of person who wants an open marriage to begin with.

Sex is powerful on its own. Love is powerful on its own. But if you combine the two, they form one of the most powerful forces known to mankind.

It's not going to be easy to just "say no." Many people, when faced with this kind of choice, will consider choosing dishonesty.

In the case of Kevin, our affair was relatively easy to end because a) I lived a thousand miles away and, perhaps more importantly, b) I didn't want to continue it from my side after I learned it had caused strain in his marriage.

But if Kevin and his wife remain open, I will not be the last woman he falls in love with.

The Secret Other Way to Address the Open Marriage Problem

Accept that you will likely both fall in love.

Probably not at the same time, but if you are in this for the long haul, you will likely both go through limerence, the honeymoon phase, and ultimately deepening of real love with someone other than your spouse.

Accept this, and decide together with your spouse how you want to handle that process when it arises. And then keep checking in.

I was once involved with another man in an open marriage (we'll call him Chris) who, after developing feelings with me, had a deep, multi-day long conversation with his wife about what love was, what it meant to each of them, and how they felt towards their other partners versus towards each other.

Chris and his wife explored the difference between "love" and "in love," and ultimately decided not to ban any feelings. Instead they decided to keep each other in the loop on emotions as they developed. They wanted to "umbrella" all other loves and intimacy under the intimacy of communication and heart-to-heart transparency they shared with each other.

My affair with Chris eventually ended for unrelated reasons, but we are still in touch as friends. He and his wife both still take other lovers, and they are as happily married as ever.

So, is Polyamory the Safe Solution?

Safer in that it offers a pre-made container for how to handle love, as opposed to denying that love will ever happen.

However, nothing in love is safe.

Even monogamy isn't safe if you look at divorce and infidelity rates: it just comes with an appearance of greater safety at first.

Safety is not guaranteed in any of our relationships, but what we can do is honestly acknowledge the challenges we are likely to face.

Since love is always a possibility when forming new sexual connections, it's important discuss with your partner how you both want to handle it when defining the terms of your non-monogamous marriage.