'I thought my husband had always been honest. One conversation with his mum destroyed our marriage.'

As told to Ann DeGrey

I always knew Lee* had been married before. He told me early on, back when we were still just dating, that he'd married young.

"A mistake in my early twenties," he called it. No kids, no messy divorce, just a youthful decision that hadn't worked out. He never really brought it up again, and I never pushed because I just didn't see the point.

We were in our mid-30s when we got together, so we both had a few messy life lessons behind us. So his first marriage was never a big deal for me.

We got married two years after we met and had our gorgeous son, Jesse*. Everything was great as we both felt settled and happy.

I had a really good relationship with Lee's mum, Debbie*. She could be a little much sometimes as she was quite loud and emotional. But she was always warm with me and she loved her grandson.

Watch: 3 Dating Mistakes Women Make After Divorce. Post continues below.

She also loved red wine and, when she drank, she had a tendency to gossip and overshare. Usually, I found this very entertaining but one night she left me feeling mortified.

There was the time she told me Lee had a gambling problem in his twenties, something he'd never mentioned.

Or the time she hinted that Lee and his ex-wife didn't exactly part on good terms; that was something he'd never told me, but I didn't bother investigating further.

Wine sure did loosen her up but they always felt like harmless stories from a different time.

I never felt like I had anything to worry about.

But one night when Lee was away for work, Debbie called and asked if she could pop in for a drink.

I always enjoyed her company so I didn't mind her coming over. She showed up with a bottle of red and snacks. Jesse was already asleep, and we settled into the couch for drinks and chats.

Somewhere between her third and fourth glass, her stories started. A cousin who went bankrupt. A neighbour's affair. And then, out of nowhere, she looked at me and said, "So, has Lee told you about Suzie yet?"

"Suzie?" I asked. At that stage, I was thinking she might be an ex-girlfriend.

Debbie looked me in the eye and said, "Yes, Suzie. His daughter. From that fling he had during his first marriage."

I laughed at first because I honestly thought she was mixing up something.

But Debbie looked very serious.

"Lee doesn't have a daughter," I said.

Debbie looked surprised and said she thought I knew already.

She said, "I mean, it's not a secret-secret."

But it was to me!

I asked her for more details, but she quickly realised she'd said too much. She tried to change the subject and told me I should talk to Lee.

I asked Debbie to leave so I could deal with this and I texted Lee immediately, asking if it's true he has a daughter named Suzie.

He didn't reply right away and, when he did, it was just saying he'd come back in the morning and we need to talk.

Well, I barely slept.

And when he came home, he looked like he hadn't slept either.

First, he apologised for not telling me the full story, then he explained. He said his first married fell apart when he had a fling and the woman he'd been seeing fell pregnant.

She didn't tell Lee she had had a baby until Suzie was three years old.

Lee saw Suzie off and on until she was twelve, and then she told him she didn't want to come around anymore.

I asked why he never told me. Why he didn't trust me with the truth from the beginning.

He said he didn't want me to see him differently. That he didn't feel like a father to Suzie and admitting she existed felt a bit shameful. I was absolutely shocked and devastated.

It wasn't because he had a daughter; that was something I could have embraced if I'd known from the beginning. But because he lied by omission. About something huge.

And if he could hide that, what else could he hide?

I tried to keep our relationship together. We did counselling and we talked a lot. But I couldn't shake the feeling that I didn't really know the man I married.

A year later, I moved out with Jesse.

Sometimes, I think about Suzie; a half-sister my son has never met. A girl who probably doesn't even know Jesse exists and that makes me incredibly sad.

When the time is right, I want them to meet. I think they should know each other. They share the same father, and that matters.

As for Lee, I still love him in a way. But I just don't trust him anymore. And that's no way to stay married.

*Names have been changed to protect privacy.

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