I’m not quite sure whether Prince Andrew calls the Queen ‘ma’am’ or ‘mum’, but apologising to your mother is one of the hardest things for a son to do.

It really is one of those stare at the floor, shoulders hunched, hands clasped tightly together in front of you, moments.

You know what’s coming once you’re uttered the words and it’s usually both barrels, to coin a military phrase.

So Andy’s heart-to-heart this week will be without doubt the most uncomfortable conversation he has ever had with ‘ma’, ‘mother’, ‘mummy’ or whatever his chosen term of endearment is at that particular moment.

Andrew has been under the royal radar for quite some time now, basking in the anonymity of his two nephews who have happily hogged the limelight.

Then just when you thought ‘Randy Andy’ had finally swapped his loincloth for warm, comfortable trousers, he is embroiled in what threatens to be the biggest royal scandal since, well … the last one.

This sort of story is Andrew’s worst nightmare.

In fact, its everyone’s worst nightmare, as a string of famous names form the worlds of showbiz and broadcasting have found out.

Half the population – those who flock to Buckingham Palace for the opening of the queen’s box of PG Tips – will steadfastly refuse to believe the rumours could be true.

The other half – those who will have seen dozens of photos of the jet-setting prince partying with a bevvy of beauties around the globe, like a sort of royal Peter Stringfellow – will be watching from afar, waiting for their suspicions to become fact.

This is one that is refusing to go away.

A hastily compiled denial from the royals was quickly followed by a second, which is almost unheard of within the monarchy’s circle of trust.

Then a photograph emerged of Andrew cosying up to the pretty blonde who is at the centre of the underage sex slave claims.

On Tuesday accuser Virginia Roberts said Andrew ‘licked her toes’ before sex.

It just gets better and better for the media doesn’t it? A story about a royal is usually enough to get the juices flowing, hang on, what? A teen sex slave too? Good lord.

That’s about as good as it gets. I know a few sub editors – and I reckon a large percentage of them, if asked at a dinner party what their dream headline would be, I imagine ‘Prince embroiled in teen sex slave scandal’, might have been top of the list.

But what happens next? Another denial? I think not. And how do the royal’s crack team of PR geniuses handle this one?

I imagine the Queen herself – who will be privy to the truth, the whole truth and nothing but the truth long before the rest of us – is having her say.

But the PR world has changed, and taking advice from a dear old lady who is precisely 88 and three quarters, is probably not the way to go.

So they will have to remain silent – officially – but not unofficially.

In my opinion their strategy should be to avoid fanning the flames of this ‘fantasist’, the light in which the royals seem keen to portray Virginia.  So saying nothing is not an option.

Silence will give the impression the rumours are true, and that behind the scenes the Queen and the rest of the family are circling their wagons ready for the looming onslaught of further revelations, as is the way these things usually emerge.

I expect we will see an increased number of quotes attributed to royal aides, containing carefully worded guidance and gentle reaffirmation that Andrew has nothing to hide, and is in fact 100 per cent innocent.

It could be quite some time before the civil case yields more information, so the palace have a long hard winter ahead of them.

When the civil case concludes, the dust may settle to but for Andrew the quest to clear his name will have only just begun.

Virginia Roberts – who may or may not be telling the truth – will be able to disappear into the darkness and get on with her life.

Andrew will then have to make a decision on whether to explore the possibility of taking action against Virginia, but for what end game?

It doesn’t seem if she is the type to, once the civil case is over and whatever the outcome is, throw her hands up and admit she made it all up.

Who knows, perhaps he will applying to Google this time next year to exercise his ‘Right to be Forgotten’

So I am intrigued to see how the royal PR machine, which has only had good news to deliver with for quite some time, plays this one out.

It’s squeaky bum time for Andrew right now.

For the record, I am leaning towards a ‘not guilty’, with the prince clearing his name in the not too distant future.

But on the charge of licking toes – the jury is out on that one.