The windows rattle and in sweeps the shade of Dame Joyce Anelay, chair of the Conservative women's national committee. Dame Joyce's spirit draws up a chair and in a reedy, but well-educated whisper reminds you of the sanctity of your vows. Then she plays her ghostly trump: if you split up now, you'll lose your fidelity bonus!
You look at each other, sigh, and admit defeat. It would be crazy to give up on your marriage now, so close to qualifying for your windfall. And come to think of it, he's not so arrogant after all, and she's not so fat. Within 10 seconds you're both upstairs locked in an unfamiliar and energetic embrace, as the gratified ghoul slips down the garden path.
A fantasy? Well, more of a discussion document actually. Dame Joyce (improbably) does exist and she did this week advocate paying a "fidelity bonus" to married couples who make it to their 10th wedding anniversary. Such a payment, she says, would reduce the nation's soaring divorce rate. So far, there haven't been many takers for this idea.
Problem one is the fidelity. A reward for remaining in the marital home for a decade has little to do with sexual loyalty. A scheme that ended up doling out cash to Cecil Parkinson and Alan Clark on account of their faithfulness might not enjoy the confidence of the nation.
Next come difficulties of definition and policing. You can imagine your accountant shaking his head and wondering out loud whether the Inland Revenue would accept the six months spent at the home of Ms Fifi Lamarr in Enfield as having been necessary for "business purposes".
And what about the inevitable crop of quickie "decade divorces" which would take place in small Scottish courts immediately after the bonus loot had been divided up?
Such are the objections that have persuaded even the Conservative MP Lady Olga Maitland (founder of Families for Defence, Conservatives for Families, Families against Foxes and Families for Nuclear Testing Close to Other Families) to pronounce the scheme "unworkable".
Now, I am a friendly and cuddly person. I greet squeegee merchants with a joke and a smile. But for some reason Lady Olga brings out the axe-murderer in me. If she's against it, I must be for it. So I am determined to find a way of making the fidelity bonus work.
We Britons are not against marriage - on the contrary, we like it so much that we do it again and again - because we are incredibly romantic. Our expectations are of undying love, unswerving honesty and total faithfulness. If we can't get them, we pronounce ourselves betrayed - and wonder whether we wouldn't enjoy life more being married to someone else.
This visceral demand for perfection means that we are prepared to lose vast sums of money in alimony, to lawyers, in moving house. So to be sure of success any fidelity bonus would have to be very large indeed: a brief consultation with tax experts in the office establishes that anything under pounds 100,000 would be unlikely to do the trick.
But alongside the carrot we must deploy the stick. What would be the use of paying out all this money just to see it immediately squandered on mistresses and toyboys? The condition of receiving the dosh must be that if subsequently a partner were to file for divorce, the hundred grand would be deducted from that person's share of the divorce settlement. Neat, huh?
With that settled, Dame Joyce and I (it's purely platonic) are ready to steal a march on Olga and announce the setting up of a new Conservative pressure group: Families Need Handouts. Want to join?