Still, we separated, my husband citing a need to go through his detox alone.

When Melissa Duclos' husband told her he didn't want the role of husband, what he meant was that it had always and only been a role to him.

My husband and I were a writing couple, communicating over the years via marginalia on drafts, cultivating a shared vocabulary, a compendium of metaphors. We referred to him as our "Chief Analogous Officer" for his habit of using analogies and metaphors to describe even the most straightforward ideas. 

Most of them were nothing more than wordplay that two writers found amusing. I didn't really think he saw the planning of our wedding as us co-managing a fantasy baseball team, for example, but we both laughed when he made the comparison. Just as we laughed when he referred to our unborn son as "Godot," though we fully expected the baby to actually arrive.

Some of his metaphors, though, I believed. When he gave me a framed photograph of Haystack Rock, he pointed at the huge boulder located just off the coast of Oregon that we had visited many times and said, "This is me." I took his promises of stability and protection literally.

It's not surprising, then, that when our marriage first started to crumble, I searched for a metaphor that would give it some weight. Our marriage is a roof, I told my husband in our therapist's office. I was craving physicality: the bulk of a structure that was our shared responsibility to hold up.

My husband crafted his own metaphors. The woman with whom he'd had an affair was, he told me, a toxic drug. He'd sought her like an addict, he said, to avoid the pain of his father's death.

After he agreed to cut off contact with her, I watched him burn unread an eight-page letter she'd written. When it was done, he said it felt as though the drug had left his system. I believed him because metaphor - like marriage - is a kind of covenant. The ashes of the letter settled beneath our fireplace grate, and I hoped they'd be a fertilizer out of which something new would grow.

Still, we separated, my husband citing a need to go through his detox alone. I convinced myself that he was simply out of his mind with grief and that he would come back to me if I gave him the space he needed. I held the weight of our roof up by myself, and though it crushed me, I didn't put my arms down.

Metaphor, I learned two months later, is a covenant easily broken. Toxic drug didn't mean to my husband what it meant to me. Alone - a word I would have previously sworn was not open to interpretation at all - turned out to be slippery as well. No words were safe anymore. Marriage, fidelity, alone, affair: Apparently, none of these words held actual meaning. The covenant of metaphor had become a conspiracy.

I sat under the roof of our house, wondering what I had been holding up, not just during the past few months of turmoil, but over the entire 12 years of our relationship. I should have paid closer attention, I realise now. When he'd told me he didn't want the role of the husband, what he meant was that it had always and only been a role to him.

The next morning, I replaced the house key that dangled from his bus pass holder with my wedding band. It wasn't a metaphor when I left it for him to pick up. It was just anger, hurt. The ring became a metaphor, though, after he carried it for three weeks, flashing platinum at the bus driver ever morning, but failing each time he pulled it from his pocket to even notice it was there.

Our marriage, it turns out, was not a protective structure whose weight we jointly bore. To my husband, our marriage was a weightless thing: easily ignored, or mistaken for something else.