I was shocked at a party recently when a woman I hardly know announced to me and another guest that she was the "mistress" of a certain man in the room.

I discussed it with my American friend in a local Italian restaurant afterwards. Holly took a robust view. "Since when does a mistress reveal herself publicly?" she said, adding that the lover (married, we’d heard, to a third wife, not present that evening) should "kick the mistress to the curb for not playing the role she signed up for." She pointed out claims that George...

I was shocked at a party recently when a woman I hardly know announced to me and another guest that she was the “mistress” of a certain man in the room.

I discussed it with my American friend in a local Italian restaurant afterwards. Holly took a robust view. “Since when does a mistress reveal herself publicly?” she said, adding that the lover (married, we’d heard, to a third wife, not present that evening) should “kick the mistress to the curb for not playing the role she signed up for.” She pointed out claims that George Bush Sr. had a girlfriend, Jennifer Fitzgerald, for about twenty years who hardly anyone knew about. “Does a mistress nowadays even have her own ‘mistress’ Instagram account?” Holly wondered sarcastically.

My friend Vicky, long divorced, was a secret mistress for twelve years. Her lover’s wife had a long-term boyfriend but the status quo was maintained. Vicky was sure that part of her charm for her lover was the secrecy of their liaisons; he was very Boys’ Own about it, pretending to his family that he was going on archaeology digs when spending time with her. At a dinner in Mallorca, Vicky was disgusted when a guest announced to the male host, in front of her husband, that she had a lover. Vicky told me her own liaison had been “deeply private” and she would have done anything not to divulge it. She added: “I liked having married lovers; they’re no trouble, easier to control — and they go away.” She added that it was difficult to find single men who weren’t flawed; “Married men are generally quite normal.” I pointed out that a mistress is probably taking unfair advantage of the hard work that a wife puts in to improve her husband.

I wonder if I, Vicky and Holly, all in our early seventies, hold views that are out of date? Carrie Johnson — installed in No. 10 when Boris was still married to Marina Wheeler — and Camilla, the long-term girlfriend of Prince Charles when he was married, possibly soon to become queen, are perhaps indications that the days of secret mistresses are over. Their power grabs have been successful — both getting their men and holding publicly acknowledged worldly positions.

Also, relationships nowadays are so hugely diverse. Remarriage is widespread (I’ve known cases where an uncle is younger than his nephew). There is gay marriage, civil partnerships and polyamory, “the practice of engaging in multiple romantic (and typically sexual) relationships, with the consent of all the people involved.”

Three characters in the Australian soap opera Neighbours — yes, I watch — recently were in a polyamorous relationship involving two men and an older woman. I found it all rather sickening (and unrealistic when at first the men seemed okay with it) and didn’t blame an older character in the soap for wanting to extricate her grandson by introducing him to a decent available girl of his own age. An article I just read featured one polyamorous woman with at least four partners. She spent most of her time exhaustingly juggling her diary to fit them all in. Where was the fun in that? Where was the burst of adrenalin and excitement involved in rushing to a secret liaison?

Years ago, on my way to a funeral in New York, our plane grounded for seven hours on an icebound runway, I was seated between two strangers of my age. One revealed to me and the man beside her that she was the secret girlfriend of a married man several rows back — part of a group going to watch a big boxing match. We both rather went off her after this. Why couldn’t she have kept it to herself? Surely it would have been more intriguing to speculate on what she was up to? Wasn’t it a bit coarse to have it spelt out?

On a sober note, George Bush Sr.’s wife Barbara suffered severe depression when news of her husband’s alleged affair (denied by both parties) was revealed in 1992 in a Vanity Fair interview with Hillary Clinton, and, in puritanical America, the news probably cost him the election. The revelation of a secret affair of a parent can be devastating, even to grown-up children, as can divorce — the family home is often sold and children feel they have to take sides.

Call me old-fashioned, but I still feel that if you’re a mistress you should keep it deadly secret — and not set out to trap the man. In compensation, you get the perks a long-term secure marriage doesn’t bring — a night in a Paris hotel, a surprise bunch of flowers, a motorbike ride through Norway, an unexpected visit. Romance.

This article was originally published in The Spectator’s UK magazine. Subscribe to the World edition here.