'I thought my husband was lying, so I spied on him. With one question, our marriage unravelled.'

As told to Ann DeGrey.

A year ago, if you'd told me my marriage would end in the snack queue of a suburban cinema, I would've laughed. But that's exactly what happened.

My now-ex-husband Sam* and I had been married for 12 years. We had two kids, a mortgage, and a lot of history.

Last year, I discovered he was having an affair with a woman from work.

It nearly broke me and while he swore it was over and promised to change, I decided to give him another chance.

But there was that little voice in my ear telling me to run for the hills, and now I wish I hadn't ignored my instincts to leave right away. So, against my better judgment, I agreed to couples counselling.

We went every second Tuesday and talked about forgiveness and "rebuilding trust."

But later I found out that I was the only one actually doing the rebuilding.

On a Friday night, I had plans to see a cheesy rom-com with my friend Lisa*. I almost cancelled because I was tired and feeling a bit irritable, but she convinced me a rom-com would cheer me up.

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We got to the cinema and were standing in a queue behind a bunch of middle-aged women like us, when I saw someone who looked very familiar at the snack counter ahead of me.

He was tall, broad-shouldered, wearing a familiar flannel shirt and a baseball cap. He looked like my husband and then I saw the profile. And the daggy shoes Sam always wore that he claimed were "timeless."

At first, I thought I must be mistaken. Sam hated going to the movies and always said the sound was too loud, the seats were uncomfortable, and "who wants to sit in silence with strangers for two hours?"

Also, he hated popcorn but there he was, ordering two large tubs of it. I nudged Lisa and she'd seen him too, laughing at something the woman beside him said.

And then I noticed the woman — blonde, wearing a leather jacket and much younger than me.

I recognised her from a work Christmas party years ago. A "colleague" he always insisted was just a friend. I stared at them and Lisa said, "You need to tap him on the shoulder and say what the hell are you doing here with her?"

We ducked back from the line, hoping he wouldn't see us. I didn't want a scene in the middle of the foyer, so I texted him a question: "How's the work function going?"

He replied, "Just finished, heading out for drinks, then I'll be home."

I almost laughed out loud. It was just such a blatant lie, and I was already feeling excited about confronting him with the truth.

I wish I'd taken a photo of him and his mistress at the snack bar, that would have been a fun thing to show him.

Lisa and I debated leaving, but I decided to stay. Plus, the movie had already started, and I wasn't about to let his latest betrayal ruin my night more than it already had.

As soon as the movie was over, Lisa and I walked out and waited. Sure enough, there was the "happy couple" who were hand in hand.

I walked right up to him. He looked absolutely horrified as I said, "Well, you're busted."

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He tried to come up with something. "This isn't what it looks like," he said.

I told him, "You're literally holding hands, we are definitely over now." I also told him not to bother coming home, and I'll see him in court.

The woman kept her mouth shut but, to her credit, she didn't try to escape. I turned to her and said, "Good luck. He cheats on everyone."

Then Lisa and I walked off like we were in a bad rom-com; it was almost too ridiculous to be real.

That was over a year ago.

The divorce went through smoothly, mostly because I refused to engage in any more of his nonsense. He moved out, and I kept the house and now I'm still rebuilding my life without him.

Therapy was a huge help and having supportive family and friends was a God-send too.

The best part? About three months ago, I heard that the "other woman" had left him, for a school dad she'd been hooking up with on the side.

Apparently, Sam had come home one day to find her bags packed. Karma, anyone?

But, seriously, I'm not bitter anymore, I'm actually quite relieved. That day at the cinema was pretty humiliating in the moment, but in hindsight, it was exactly the wake-up call I needed.

You can't rebuild trust with someone who keeps tearing it down, so I'm in a much better place.

Names have been changed to protect privacy.

Feature Image: Getty. (Stock image for illustrative purposes only).