‘Some people just won’t get it,’ says GoodNews.

‘Some people might need the spare rooms for other things,’ I say.

‘Like what?’ David asks, slightly aggressively. He used to use exactly these tones when he wanted to challenge me in the old days—about why I wanted to teach the kids about other forms of religion, say (he didn’t want them to know about any), or why I wanted to go and hear Maya Angelou read (‘What, you’re a black feminist now?’). I had forgotten how wearing these tones were.

‘You used to work in one of ours, for example.’

‘OK, so five out of the forty are used as offices.’

‘And what about if people have their parents to stay?’

‘God, you’re literal-minded.’

‘What’s literal-minded about saying that people have parents?’

‘It’s not that. It’s the spirit. You have none.’

‘Thank you.’

‘None of these things are real problems. You’re just being negative.’

‘You have no idea about these people’s lives. You don’t even know their names.’ I gesture at the paper in front of them. ‘But you’re happy to tell me what’s a real problem for them and what isn’t. What gives you the right?’

‘What gives them the right to own half-empty houses when there are all these people out there in cardboard boxes?’

‘What gives them the right? Their bloody mortgages, that’s what gives them the right. These are their homes, David. And it’s not like they’re enormous homes, either. Why don’t you pick on Bill Gates? Or Tom Cruise? How many spare bedrooms have they got?’

‘If they lived around the corner, I would pick on them. But they don’t. And we don’t need them, because there’s plenty of room for everyone right here. You’re just frightened of the embarrassment.’

‘That’s not true.’ But it is, of course, completely true. I am terrified of the embarrassment, of which there will be lorryloads. I can hear the diesel engines rumbling towards us even as we speak. ‘How do you plan to go about this, anyway?’

‘I don’t know. Door-to-door.’

‘What about a party?’ says GoodNews brightly. ‘We’ll have a party here, and you can speak to everyone, and… and it’ll be great.’

‘Brilliant,’ says David, with the air of someone who knows he’s in the presence of genius.

‘Brilliant,’ I say, with the air of someone who wants to put her head in the oven. But that sort of air doesn’t interest them in the slightest.

OK: so they’re wrong, clearly. And also completely mad. It’s just that I can’t quite work out why. What is the difference between offering spare bedrooms to evacuees in 1940 and offering spare bedrooms to the homeless in 2000? You might point out that the evacuees were in mortal danger; David and GoodNews would point out that the street kids have a lower life expectancy than the rest of us. You might argue that in 1940 the nation was united in its desire to look after its own; they would say that it is precisely this spirit we need now, for similar reasons. You could laugh at them, and say they were pious and sanctimonious, holy fools, moral blackmailers, zealots; they would tell you that they don’t care what you think of them, that there is a greater good at stake. And do we have a moral right to keep a spare bedroom as a junk room, or a music room, or for overnight guests who never come, when it is February and freezing and wet and there are people on the pavements? Why isn’t a standing order with Shelter enough? And what if my husband, or GoodNews, or both of them, turned out to be Jesus, or Gandhi, or Bob Geldof? What if the country had been crying out for this kind of energy, and they revolutionized the way we thought about private property, and homelessness was never again a problem in London, or Britain, or the Western World? What about my embarrassment then?

I no longer have the answers to any of these questions. All I know is that I don’t want this party, and I don’t want to put my neighbours through this, and I wish David and GoodNews were interested in starting up an Internet company so that they could make millions of pounds to spend on Page Three girls and swimming pools and cocaine and designer suits. People would understand that. That wouldn’t upset the neighbours.

David and GoodNews tell the kids about the party the next morning at breakfast. Molly is curious; Tom sits at the table playing on his Gameboy and eating his cereal in between lives, apparently uninterested. I sit between the two of them while the men lean side-by-side with their backs to the work surface, answering questions. It is impossible not to notice how the dynamic in this household has changed, how my place now is with the children. And I don’t mean that in the maternal sense, either; rather, I am reminded of going to large family parties when I was fourteen or fifteen, when there was always confusion as to whether I should sit with my younger cousins or with my aunts and uncles at mealtimes.

‘Are we going to get a homeless person to stay, too?’ Molly asks.

‘Of course,’ says David.

‘Haven’t we got ours already?’ I say, with meaningful looks at all the relevant parties.

‘So who else will get one?’

‘Anyone who wants one,’ says David, and his reply makes me snort with laughter. Anyone who wants one… It’s Christmas, and this year everyone wants a homeless person, just as a couple of years ago everyone wanted a Buzz Lightyear. But at the homeless shop they never go out of stock.

‘Would you like to tell us what’s so funny, Katie?’

That’s what he says, I swear. And he even sounds like a teacher: stern, vaguely distracted, following a script that was written a hundred years ago.

‘That’s not the line,’ I say. I suddenly feel that, as I am the oldest child, it is incumbent on me to be the naughtiest. ‘The line is, “Would you like to share the joke with the whole class?” ’

‘What are you talking about?’

‘I get it,’ says Tom. ‘Don’t you get it, Dad? You’re the teacher and Mum’s being naughty.’

‘Don’t be silly.’

‘It’s true,’ says Tom. ‘That’s what you sound like.’

‘Well, I’m very sorry. I don’t mean to. Anyway. Is everybody happy about this?’

‘I’ve got a question.’ Sitting at the table with the kids, and being told off like a kid, has liberated me; my disenfranchisement has empowered me.

‘Yes, Katie.’

‘What happens if a homeless person moves into a neighbour’s house and cleans them out?’ It takes a child to say the unsayable.

‘What do you mean?’

‘I mean… well, that. What if we assist in moving a thief into our neighbour’s house? Someone who’s broke and desperate with a drug habit?’

‘You’re stereotyping the homeless, Katie. I’m really not sure that’s the right way to go.’

‘I appreciate what I’m doing, David. It’s just, you know… The stereotype of a football fan is someone who gets drunk and breaks bottles over people’s heads. And I know it’s a stereotype, and I know lots of people who go to Arsenal who aren’t like that. Just… There might actually be one or two who are. And I’m not sure I’d like to tell Ros and Max that they have to live with them.’

‘I just don’t think this conversation is very helpful.’

‘Have you even thought about it?’

‘Of course not.’

‘Right. Are you going to think about it?’

‘No.’

‘Why not?’

‘Because I want to change the way people think. And I can’t change the way people think if I think like everybody else, can I? I want to believe the best of everybody. Otherwise what’s the point?’

There are many, many answers to that last rhetorical question, but I can’t bring myself to utter any of them. I shake my head, and get up from the table, and go to work, so that I can become an adult again.

Except, of course, work too has now been altered by my domestic circumstances, and when I get to the surgery, Dawn, the receptionist, is standing behind the desk with her mouth open and her brow furrowed, trying to make sense of a lot of very old European ladies waving their hands in the air and saying ‘Hot! Very hot!’, and miming sudden sprightliness (which, because they are not sprightly in any way, they have to effect with their eyes, mostly), and trying to look sad.