Something very strange happens to men as they get older: they like to go nude. I don’t mean they become practising nudists who seek out and enjoy the company of others of their kind. But unlike most younger men, they feel no embarrassment or regret at being seen naked.

Consider the recent battle between one nude man and his neighbour. Simon Herbert (54) was in his Oxfordshire garden mending a fence when he spotted his next-door neighbour — Air Marshal Andrew Turner (54), the RAF’s second-in-command — strolling naked in the paddock of the cottage Turner shares with his wife. Herbert says that his partner and stepdaughter caught an eyeful of the nude air marshal too. The ‘shocked’ Herbert family are demanding a ‘proper apology’ for the distress they’ve suffered.

The naked air marshal is in good company. While staying at the White House as a guest of Franklin D. Roosevelt during the second world war, Winston Churchill, who had just come out of the bath, appeared naked in front of FDR. It’s said that Churchill was making a joke about the special relationship. But the American president was not amused. To paraphrase FDR, there are things we have to fear more than fear itself — and one of them is the naked older man.

You know when nudists are about: their territory is well marked with signs and warnings. Not so with a naked man. You’re going about your business when suddenly up he pops. He can be your husband, your dad, a friend of the family or even a stranger. Such men may not have the malicious intent of the flasher or the lechery of the masher, but that doesn’t mean they’re totally harmless.

Just one accidental peek at their privates can cause extreme emotional distress or a near-lethal surge of embarrassment. I know a woman who has never recovered from seeing her father-in-law naked on a summer holiday two decades ago. ‘Not only did he make no attempt to cover up his dangling bits but he just stood there making polite chitchat. For a time, I couldn’t look at my husband without seeing his naked dad.’

As a teenager in the 1970s I sometimes caught sight of my naked dad, whose bathrobe would just suddenly and mysteriously part, revealing all to me and, on occasion, my girlfriend. My anguished pleas for modesty were dismissed by him as mere prudery. But then he was an old bohemian who believed in letting it all hang out. I know of teenagers who still live in a state of terror that their usually discreet dad or reserved grandparent will suddenly pull a nudey on them. One of them tells me: ‘Show Dad a bit of blue sea, let him feel some sunshine and before you can say “Please Dad, don’t!” he’s stripped and strutting off for a swim, todger and bottom flapping in the breeze. It’s so embarrassing!’

But we men must suffer the spectacle of nude men too. Every changing room in every gym comes equipped with showers, soap, hairdryers and at least one naked old guy. Not for them the concealing towel around the waist. They just strut happily around the place, baring all, talking to other old naked guys about their prostates, while nervous young men are putting their clothes on as fast as they can. Even the Palace of Westminster is not immune. One former staffer explained: ‘The parliamentary gym can be a very off-putting place. It was not uncommon to see peers of the realm striding around totally starkers, chatting conspiratorially.’

Nude men — and their motives — come in numerous varieties. There’s the chap who is not flaunting his manhood but showing everyone he’s above caring about what’s down below. It’s the entitlement of age; it feels good, so why not? Then there’s the nude guy who likes to show the world that despite his age he remains a bit of a rebel. He keeps himself in good physical shape and hopes that women will see that he still has it. The liberal nude man likes to believe he’s doing it for a good cause, much like those feminists who go topless to challenge sexism.

Was the aggrieved Simon Herbert making a big fuss over nothing when he saw the nude air marshal? Possibly. But when a man appears naked in public isn’t there always something dark lurking beneath his innocent intent? After all, there’s nothing more passive-aggressive than having everything out for all the world to see. Perhaps it’s a territorial thing; animals spray, men display. Me, I’m all for nude man liberation — as long as it doesn’t scare the neighbours.