It's all lies - Michael Jackson's the greatest] So far, that has been the stock six-year- old response to the recent allegations of sexual abuse. But the multi-million-dollar pay-off believed have been offered to Jackson's alleged teenage victim (although Jackson denies the allegations) is likely to make even the most dedicated young fan think again.

The fall of an idol is nothing new. In the adult world, scandals about politicians and soap stars merit little more than a cynical smile. But Michael Jackson is a special kind of hero because his fans are so young, because he means so much to them, and because he has been accused of abusing someone not much older than they are.

Pippa Bradshaw is the mother of eight- year-old twins. 'To them Michael Jackson was a total superstar hero - they just loved him. They wanted to dance like him, sing his music, and they went on about what a kind, charitable person he was and how marvellous he was with animals and children - they completely believed in the image. Now the bubble's burst and he's become more of a figure of ridicule. It's disillusionment - they don't believe in him any more.'

Ever since the story first broke, parents have dreaded their children's questions. One family I know takes pains to hide newspaper references to the allegations from their eight- and ten-year-old boys, and they stop talking about the case when a child walks in. Other parents skirt round the issue with vague answers and hope there won't be a demand for specifics.

Julia Bateson, who has four children under nine, went one step further: 'When James, the eldest, saw the news reports, he asked me what 'abuse' meant. I explained that Michael Jackson was suspected of being cruel to a child. Then he wanted to know what 'molest' meant, so I told him it meant playing with children's private parts and being a bit rude. That was enough to satisfy him. I found his questions quite easy to answer.

'Then one day, in the car, he and a schoolfriend came out with a Michael Jackson joke with the punchline: 'Don't let your son go down on me.' I just said, 'I don't really understand that joke,' and all the children said they didn't either, and we left it at that. If James had asked me a direct question about it later I would have given him a straight answer, but when you're in the car with someone else's child and you're trying to drive, the last thing you need to be explaining is fellatio.'

Gill Wren, a social worker whose two older sons used to be keen Michael Jackson fans, has been more frank about the allegations than many parents, perhaps because of her experience with the victims of sexual abuse. Her sons' bedroom walls are still plastered with posters, but since the allegations the edge has been taken off the hero-worship. 'We talked a lot about the allegations. I tried to put it into context by talking about Michael Jackson's childhood, which he talked about in the Oprah Winfrey interview. We talked about how he didn't have an ordinary childhood and I said he's not an ordinary person and he might have problems: he might not be able to make friends with adults so he chooses all his friends as children. But that it wouldn't be right for him to have a sexual relationship with a child because children aren't old enough.'

For all parents the difficulty lies in judging how much information children can handle. If an eight-year-old wants to know how a grown-up man can have sex with boys, for example, should parents embark on an explanation of anal intercourse? To some extent, it must depend on how much a family has already discussed sex. If a child doesn't grasp the basics of heterosexual intercourse, it's hardly appropriate to talk about more exotic behaviour. It is probably better to simply say that he was accused of touching a boy in places and ways that he didn't like.

Many professionals see the case as a positive opportunity to raise issues of sex abuse and inappropriate touching. Their standard response to the parents' dilemma is that if a child is old enough to ask a question he or she is old enough to receive an honest answer, as long as it is carefuly pitched at his or her level. Judging how much information to give without creating unnecessary anxiety may be easier than it sounds if parents take the lead from the child and stop giving information when the questions stop. Most parents find that their children wander off when their curiosity is satisfied.

Gill Wren says: 'I think it's important that you answer as much as they want to know. If the boys haven't heard enough or they don't understand, they keep asking. If they had asked me how a man can have sex with a boy I would have said, but I don't think they have that much understanding of it. It's a question of finding the words or the context that makes sense to them.'

Pippa Bradshaw thinks her twin sons have learnt a valuable lesson about how hollow a public image can be: 'The discussions we have had about the case - whether Michael Jackson is telling the truth, what he was accused of doing, what people's motives are - are the stuff of reality, whereas the stuff before was all fantasy and illusion. It hasn't been shocking or upsetting for them, it's just that he's changed in status: he has ceased to be something out of the ordinary. But they still like his music.'