All best wishes to venerable rocker Sir Mick Jagger and his ballerina girlfriend Melanie Hamrick, whose little boy was born last week.
A baby is always a cause for celebration and fuss, and that is as it should be. But...
Oh dear, I'm going to sound all churlish now, aren't I?
But is fathering children at the age of 73 a cause for celebration? This much-wanted new arrival is 29-year-old Melanie's first child. Lovely. No one would wish to deny her the right - the joy - to be a mother. He is, however, great-grandfather Sir Mick's eighth child, and that's where it gets complicated.
His eldest child, Karis Hunt Jagger, is 46 years old. His second youngest child, Lucas was born in 1999, making him now 17. Sir Mick also has five grandchildren and his first great-grandchild - a girl born to his 45-year-old daughter Jade's daughter Assisi, 24, in 2014 - is now two years older than her newborn great-uncle. At least I think so. I might have to ask Stephen Hawking.
I know Sir Mick is a rock star who will live forever and all that (even if he did once say he'd "rather die than be 45 and still singing Satisfaction"), but there is something reckless, if not feckless, about fathering a child he almost certainly won't see into adulthood.
Here in the real world, a union between a 73-year-old pensioner and a 29-year-old woman would be regarded as freakish and unnatural, the gap too wide for our established social mores.
But when pillow-lipped Jagger sets his cap at someone young enough to be his granddaughter, it's accepted as yet another perk of fame and fortune.
We've long acknowledged F Scott Fitzgerald's observation that the rich are different from you and me; with wealth comes choice and with choice comes freedom, and that includes the freedom to kick over the traces of convention. And nobody doubts that this new Jagger will be unquestioningly accepted into his rambling, complicated family set-up.
These things happen, of course, but it's hard to escape the suspicion that fathering children late in life has possibly become a badge of honour and proof of youth and virility.
Virility? Absolutely. But youth? No. Immaturity, possibly.
Let us hope such late-life reproduction will remain a rarity; some studies suggest older fathers run a high risk of passing on genetic abnormalities and conditions such as autism and schizophrenia.
It might sound like scaremongering but it is biological fact; the menopause shuts women's reproductive system down once their egg quality has deteriorated. Men must rely on common sense, rather than nature.
But for those used to the adulation - adoration - of millions, common sense is far too pedestrian a concept. The external pressures, not just from a younger partner keen to have a baby, but legions of fans also inevitably have an effect.
"People have this obsession," Sir Mick once said. "They want you to be like you were in 1969. They want you to, because otherwise their youth goes with you."
New relationships are exhilarating, but new babies are exhausting for a dad in his mid-thirties, never mind a septuagenarian.
I'm sure Sir Mick will cope, in whatever form that takes (he can afford a separate wing, not just a separate bedroom) and I wish his new little family unit a lifetime of good health and happiness.
In the years to come, this child will want for nothing. Except perhaps for a father. And sometimes that is the biggest loss of all.
Telegraph, London