General grounds for refusal - False representation

I am applying for a UK Spouse Visa.

There is a question "Have you ever: Given false information when applying for a visa, leave to enter, or leave to remain".

I initially answered "no" because, surely I'd never done that?

But then I realized, I had been scolded by a Border Force Officer.

The first time I flew into the UK with my then-girlfriend (now wife), I was asked about the purpose of my visit, and I never mentioned her or visiting her.

We travelled a month later, and when we reentered the UK, the Officer this time asked if I had a UK partner, and I answered that I did, and we had just arrived together. Now I was taken aside, and waited 15 minutes until I was brought back to the same officer, who gave me 6 months Leave to Enter, but scolded me, informing me that I was to always let them know that I had a UK partner.

Now of course I'm terrified that my visa will be refused, as deception is mandatory grounds for refusal. I wasn't asked the first time if I had a UK partner, but I also didn't mention her as part of my reason for visiting. Obviously I didn't understand that I absolutely needed to have mentioned her. And I was honest when asked directly on my second visit.

Does anyone know if I explain this in my visa, if I'll still be denied? Does it help that I told an Officer the second time, and was granted Leave to Enter, and was informed I needed to always mention her in the future?

From OP: I did initially answer No but then the thought jumped out that I was mistaken. I was asking on this forum, to help me figure out whether to answer Yes or No, what to say, and how the answer would weigh on my application decision.