The day we told our neighbours we had to demolish half their house

So we're sitting there sharing a cup of tea and a chocolate chip biscuit with our upstairs neighbours and every minute the conversation is edging towards the inevitable.

"So how bad is it? What will you need to do to repair it?"

The "it", of course, is.... the blot, the £20,000 question, the end of the house of which we do not speak, the room behind the door which is shut where we keep boxes of rubbish CDs, old letters and lots and lots of guitars (don't ask). It is the small question of the far end of our home sliding millimetre by millimetre into the latent floodplain of the Thames. We are sinking. And no-one thought to tell us before we bought it.

"Well," says my Dad expansively, "one of the things they might try is to prop it up."

"And what would that involve? How would they do that" says our neighbour slowly, he's grasping towards it, the cat is sharpening its nails and getting bored of its brown paper prison....

"Oh well," says Dad, adding comfortingly skating over the real issue with technical phrases such as "steel joist" and "RSJ".

Tom and I are desperately trying to maintain a serious, graven expression of concern as if it's all news to us too.

Then suddenly, without warning, its out! "Worst case scenario is that all this has got to come down," Dad says, standing on the balcony gesturing at the floor and the kitchen. His hands gesture the wall of their house away, he sweeps aside the roof and we're all standing on the ground floor surrounded by rubble.

I'm biting my lip, you've got to laugh really... haven't you? "I wanted a new kitchen anyway," says Gillie (or Ginny, after a year we're not sure), laughing to make us all feel better about it. But Anthony (previously Patrick) looks white, showing no trace of amusement.

And then we're off, thanking them for the evening, like we've all had a jolly time and they're not going to dream of demolishing balls and dust and destruction of their lovely home. I feel wretched about it, but the moggie is well and truly out of the bag.