The other day, one of my friends asked Megan what it was like to be living at home with her family at the age of 26. Megan thought for a moment and said: “Now we’re grown-up, it’s like living in a commune.”

I was startled by Megan’s choice of simile, but the other kids nodded sagely: yup, just like a commune.

I can’t deny that we’re a group who live together, and that four out of six of us dress entirely in jumble-sale clothes, so in some respects I could see where she was coming from. But the definition of a commune, I pointed out, is sharing possessions and responsibilities, and being equal in all things. They looked at me with bemused expressions. “Like us,” Lily said.

In their minds, they do their fair share of taking out the bins, emptying the dishwasher and putting away the shopping. All of us take it in turns to cook and wash up. To them we are indeed living in a share-and-share-alike world. But, just as Zac can’t see the mess in his room, none of them can see that, really, they are still living by the child’s logic of what’s yours is mine and what’s mine is mine.

Any treats – chocolate, for example – I put in the spice drawer, otherwise they will get wolfed down by one of the kids

Leaving aside the small matter of the mortgage and utility bills, take the subject of food – the thing that causes the most arguments in our house. We all eat the food. We all cook the food. But only Ed and I buy the food. This would not go down well in a commune.

The boys have bottomless stomachs when it comes to cereal and toast, and snack on vast quantities of fruit and vegetables. Wars break out at the opening of the fridge door. Lily becomes distraught when there’s no more yoghurt. Zac is furious when someone has eaten the last of the hummus. Fed up with finding that the ingredients I had earmarked for a recipe have disappeared, I have resorted to storing things in the shed, which is fine if it’s not raining, otherwise I get soaked in the act of going to make a meal.

Any treats – bars of chocolate, for example – I put in the spice drawer, otherwise they will get wolfed down by one of the kids. Megan and Lily, already keeping their boxes of herbal tea in weird places, also hide food that they buy themselves. Giant tubs of peanut butter and bags of nuts and seeds are stuffed behind pots and pans, or wedged between the baking trays. We have become a family of squirrels.

Even Ed is in on the act. He keeps forbidden digestive biscuits at the back of a cupboard full of Tupperware boxes. We all know where the others are hiding their food, but the fact they have been hidden makes them off-limits. That doesn’t stop Megan examining her tub of peanut butter suspiciously and accusing Jake of stealing some.

Megan, the most enthusiastic of the cooks, will often bake delicious brownies or biscuits and offer them as a pudding. Our eyes light up as our fingers reach for the delicacies. But she can’t resist saying: “Just one each. I bought the ingredients with my own money.”

That’s the trouble with having twentysomethings at home – it makes them suffer from a delayed onset of adulthood. They still think their hard-earned money is just for them. Perhaps I should demand my cut to go towards the weekly food bill but, because they are studying or saving up to move out, I feel bad asking for a donation. Jake did once contribute on a regular basis, but this led him into having a sense of entitlement and a proprietorial attitude towards all food that did nothing to quell the fridge riots.

I tell Ed about the commune comment. He’s reading the paper and not concentrating. “Hmmm. Never found the idea of a commune tempting.”

“That’s not what I’m saying.” I talk slower and louder. “Obviously we’re not living in a commune. We pay for everything.”

Seeing my point at last, he gives a bitter laugh. “Perhaps we should pack them all off to a real one,” he says. “Give them a taste of what it really means.”

“Do they still exist?”

We give each other hopeful stares. “Pass me my laptop,” he says.

Some names have been changed