As Christmas flies round again, some Chinese friends have asked me how we can justify lying to our children about the man in red.

"Mom, why doesn't Father Christmas come to my Chinese friends? They say he isn't real!"

"And that's why he doesn't come sweetie. He only comes to people who believe in him."

"But we haven't got a chimney."

"He builds one when he gets here."

"Shall we leave him a nice cup of hot chocolate when he gets here?"

"No, he doesn't like hot chocolate. He likes dry martinis with three olives."

The whole season has prompted me to dispel one of the greatest myths about good parenthood - that it is wrong to lie to your children.

Despite many magazine articles and claims by parents who insist that telling lies to your children is sinful, it is my strong belief that there are many occasions when it is perfectly permissible, as long as you don't get found out.

Sometimes when I have to go out in the evening, I pretend to my child that I'm going to bed, then when I am sure he is asleep, change clothes with the speed of light, slap on some makeup, the neighbor comes round, and off I go.

If I had told him she was coming, he would have waited up to see her. They would have played until 11 pm and an exhausted child with a huge mood the following day would have been pure misery for everyone.

My neighbor is already primed - should he wake up, I receive an urgent call from a friend asking for help so I went out for a couple of hours. Not a total lie. He did call - just a few hours earlier.

My Chinese friend used to be quite adamant about always telling the truth to her little boy, whose voice is enormous.

She and her son accompanied me and mine to a recent Christmas fair, where there was a beautiful display of chocolate Santas.

One little voice, and one huge voice, clamored for one each.

"Oh, they're poisonous," I fibbed to my child, grimacing as I waited for my friend to tell him with the voluminous voice box the truth, with the inevitable ensuing din of complaint.

Suddenly I heard her say, "Yes, they put poison in them to stop people stealing them."

Is the truth - that they are really over priced, will probably taste like dog chocolate will inevitably only be half eaten anyway - better?

Maybe, for children who will nod and say, "Ah, I understand. Quite reasonable Mom, no, we won't get one then."

But for children who will whinge on with that head-splitting voice, it is my belief that it's simply better to tell them the chocolate Santa will kill them.

In the summer, we often go walking in the countryside. There is a wild pond, about two hours' walk away, full of frogs and fish and my little boy loves going there, as do I.

Unfortunately, he is extremely lazy, has to be constantly coaxed into putting one foot in front of the other, and it's a real pain.

Sometimes he waits until it is almost dark to insist on going. And when I cannot face the thought of cajoling him every step of the way and probably having to carry him back, yes, I have been known to tell him that the pond only gets put there on certain days. Or is closed. Or only ever existed in his imagination, perhaps.

Two of my Chinese mother friends have already started to take part in the Father Christmas illusion. The other day, I overheard a mother in the street chatting to her child about it. So it's taking hold, and I really hope it spreads.

The rapt faces on Christmas morning when the realization dawns that this mystical being has been is priceless. And I don't know any adults who are angry with their parents now for giving them one of their most exciting childhood memories.

So long live the lie - this one, anyway.