Now I will have to scrape that small piece of potato into the bin, I think. Am I not busy enough? Why could she not have eaten it? It's just a tiny piece of potato!

I risk it.

'Do you want this piece of potato?' I call out.

'No thanks,' she shouts, from the sofa. 'I'm full.'

I stare at the tiny piece of potato.

Full? I think. No one can be that full! It's the size of three peanuts! Even Morph would ask for seconds!

It would be better if this were some kind of eating disorder, but it isn't - it's something she read in a magazine about leaving the last bite. I quell my annoyance and sit back down to watch The X Factor. Dannii Minogue is telling someone they really made that song their own.

I cannot concentrate.

'In some cultures,' I say, curtly, 'it is rude to leave bits of your food lying about. It means you don't like it.'

'In other cultures,' she says, calmly, 'it is rude to eat everything on your plate, as it implies you have not been given enough.'

'Well, neither of those are our cultures,' I say. 'Or are you saying I have offended your culture?'

'No, you have not offended the Australian culture,' she says, and I have to stop myself saying something racist.

A moment passes.

'Whenever you bring me toast,' I say, 'there is always a bite missing. Perhaps if the "mouse" you sometimes blame this on weren't quite so hungry, it would be able to eat tiny bits of potato left on your plate.'

There is a pause.

'That's not really a mouse,' she says. 'It's me.'

I knew it.

But I decide to leave things there. I have made my point.

Two nights later, we are at a very posh restaurant. The food has been incredible, and we've laughed and laughed. I've cleared my plate of extravagant South Indian food and she's pretty much finished hers, apart from a lonely prawn sitting atop a tiny stamp of rice. Soon, the waiter is upon us. He picks up my dish, and then goes for my wife's, but stops ... 'I'm so sorry,' he says. 'I thought you'd finished.'

'I had!' says my wife, smiling.

'But -' He turns to me and raises his eyebrows before turning back '- you still have one or two prawns left!'

He smiles, as if there's been a terrible mistake he's trying to make easier, and waits for our response. My wife looks to me for support.

And I smile at her.

Because this is what I've been waiting for. This is confirmation. Independent confirmation!

'Oh yes!' I say. 'There it is! Just a tiny prawn all on its own!'

I point at it. My wife widens her eyes.

'But I'm full,' she says, slowly.