My partner and I opened our relationship, and I was surprised by how close I became with his girlfriend

• Rachel Krantz is an internationally award-winning journalist and author.
• The following is an adapted excerpt from their memoir "Open: One Woman's Journey Through Love and Polyamory."

When my partner Adam asked what I thought of his girlfriend Leah coming out to visit for his birthday, I pragmatically decided to view it as the next step on my path. I'd read in "The Smart Girl's Guide to Polyamory" that one of the best ways to combat jealousy was to meet your metamour. Since she would be coming to visit for a week in August (a whole week straight!), I decided to reach out. And thus began the most texting-intensive relationship of my life.

Indeed, it was actually a huge relief to text with Leah. Our exchanges were overtly kind; we were both going out of our way to signal politeness. It reminded me of how some femmes will reflexively compliment something about your outfit when they meet you at a party, as if to say, "I come in peace." Or is it a keep your friends close, enemies closer kind of thing?

Leah was deferential to my "primacy" in a way that made me feel like she had no interest in stealing my place. She did this by sometimes saying so directly, but also demonstrated it by rarely referencing her relationship with Adam at all. The same unspoken code didn't apply to me, with her making generous references to admiring our "primary relationship." But I tried not to talk about Adam in any way that might come off as bragging.

On the rare occasion she did mention Adam with romantic undertones, I'd feel a twinge of jealousy, a feeling that it was somehow a passive-aggressive power play. And then I'd consciously try to shut the thought down, because it was unfair.

I became close to my partner's girlfriend, Leah

When it came to everything but the man we "shared," we were almost compulsively forthcoming. We dished about sex (except sex with Adam) in the kind of detail I'd seen on "Sex and the City." Was it because we shared the same man? Were we backhand bragging? Bonding? All of the above, I'd suspect. Soon, we could even commiserate over Adam's newer romantic prospects like more senior sister wives; admitting how attractive they were, the precarious feeling of constant competition.

I soon became very protective of Leah's well-being, a sort of on-call counselor. I found she was sometimes even more anxious, insecure, and neurotic than I was, which was really rather impressive/a little disturbing. Is this Adam's type? No matter. Now that she was a real person instead of an abstract threat, what was important was Leah was no longer she-who-must-not-be-named in my mind.

I was even able to talk with Adam about her like a mutual friend. Sometimes, I knew things that were going on with her before he did. That felt good, too, like I was less excluded and more in control. Leah and I congratulated ourselves often on our friendship. It was a choice we were making, and not an easy one, not to cast the other as the enemy. It felt not just evolved, but laced with real sisterhood.

Though Leah and I were now texting daily, she called me for the first time after I experienced a particularly bad romantic disappointment with a new man. This new guy, who I thought really cared about me, who I was getting legitimately attached to after being friends for months first, didn't even consider me enough to get tested like he'd promised before I traveled hours to see him. Or warn me about what turned out to be genital warts.

This was now the second time that a guy hadn't disclosed an STI until after I'd been grinding on his underwear, taken it off, and inquired. I'd never encountered something like this before being in an open relationship. But now that I was an openly non-monogamous woman, the men I would date (only one of whom actually identified as non-monogamous rather than "just dating") treated me in ways I had been lucky enough to mostly avoid before: coming on my body without asking. Violating boundaries around condoms. Not disclosing STIs until the heat of the moment, even attempting to hide outbreaks.

People assumed I was only looking for casual sex

But for me, the worst insult would prove emotional. The way in which I was now considered "already spoken for" and therefore somehow immune to attachment. The way it was assumed I wouldn't catch feelings, or want to be loved and treated with the usual care. After a decade of being considered girlfriend material, I was now experiencing what it is to be treated by men as if I was little more than an amusing pit stop on the highway to arriving at Respectable Womantown. That it was assumed casual sex was all I was available for, or wanted? It was frustrating and hurtful, to put it mildly.

It remained easy for me to find dates or sex as a woman in an open relationship. But when it came to finding people who offered actual intimacy, it seemed Adam had the upper hand. For one, he wasn't constantly anxious, projecting rescue fantasies onto everyone. But these other women he dated also seemed far less likely to see him as just an amusing sexual romp.

If anything, I suspected that his being with me increased his market value, even if women were initially more cautious. That he was already with someone perhaps proved he was worth keeping. It seemed that my already having a partner made men see me as more sexually loose and fun, but less potentially valuable. I was already "owned" and therefore used goods — nicely broken in to borrow and return.

That I myself had increasingly begun to devalue sex and my body perpetuated this cycle. By this point, sex was mostly just another drug; either it was strong enough to ignite Adam's lust and distract me from jealousy — or it was insufficient. Given this consumerist mentality, it's no surprise I had trouble attaching to people, or attracting the types of people I might want to attach to me.

Whatever the reasons for getting the short end of the dick, I felt my dynamic with Adam needed to be more "even" — a rookie polyamorous mistake, since this is pretty much always an impossibility. Now that I'd set him free again, he was going on at least one, sometimes two, other dates a week. Everything felt like it was moving too fast, but I didn't want to pull the emergency brake again and end up ejected.

Adapted from Open: One Woman's Journey Through Love and Polyamory copyright © 2022 by Rachel Krantz. 2024 Harmony Trade Paperback Edition. Copyright 2022 by Rachel Krantz. Published in the United States by Harmony Books, an imprint of Random House, a division of Penguin Random House LLC, New York.