There is no easy way to write this, so I may as well dive straight in: one of the most famous and most photographed men on the planet is losing his looks - and fast.
It must be tough for Prince William as it won't be long before we're seeing his face on everything from our bank-notes to our stamps.
And yet a decade ago it had all seemed to be going so well: William was a great looking guy.
He was tall, he was fit, he had swimmer's shoulders and a winning smile; he had pretty much everything you could want from a Prince Charming.
And now, 10 years on, as I looked at the footage of him and his wife in Cambridge last week, I realised that his good looks have gone. Of course he's still tall and lean and he's got those great teeth. He's still got the smile.
But as for the rest... It seems that William is taking a little after the Spencer side of the family. He is developing the rather heavy-set look of his Uncle Earl Spencer.
Then there's the hair.
It must be a good move for William to go with his recent short-cropped hair. He's thinning and proud of it.
But the truth is that for the first time since the Norman conquest, Britain will soon have a bald king. (But not the first bald monarch - that was Queen Elizabeth I)
I wondered if I was being unfair to the Duke of Cambridge. I asked a number of women friends. Is it just me - or has he gone off the boil?
The verdict was unanimous. William is nowhere near the pin-up that he once was. Years back, he was a poster-boy. Today, it would be quite a stretch to imagine his picture up on any girl's bedroom wall.
But let's get to the nub. Does it matter - in the slightest - if our future King is not a dish? Does it matter if Prince William is not up there with the rest of the Euro-hunks like Prince Felipe of Spain or Prince Haakon of Norway?
And the answer is... well maybe.
Britain's Royal Family has no actual power, but what it does have is influence. It has clout. The Royals talk and people listen. Witness all the dozens of letters that Prince Charles has written to politicians over the years. He's not doing it for his health.
So - are people more likely to listen to men who are handsome? Will your message be better received if you're a good-looking guy?
And again - maybe.
One thing that's undeniable is that pictures of good-looking guys are much more likely to make it into the papers and onto the internet than pictures of plain-looking men.
What is happening with William is that when he's out on tour with his wife, then the pictures that we see are invariably of Kate just by herself. We see very little of William. That's how it is around the world. Picture editors will always go for pictures of Kate over pictures of William.
So in ten years' time, will William still have the global recognition that he does today? Though he is a Royal, he is also a superstar - and politicians and superstars like to hang out with superstars.
Without the publicity, will people still be turning out in their thousands to see him? Will world leaders still be hanging on his every word, when they can see that their voters are indifferent?
Of course it would be just lovely to say that a man's looks are as irrelevant as his skin-colour. But is that really the case - or is that just a sop to the politically correct?