NEW YORK • Whenever unlikely lovers pair up, onlookers are rarely without an opinion or the kind of noises you would expect from third-graders shown videos of childbirth. It does not matter if the couples' unlikeliness is based on their disparate ages, their levels of attractiveness, status, physical size or race.
It seemed only inevitable that the British gossip website Popbitch would invoke the phrase "Gruesome Twosome" to the recent marriage of Mr Rupert Murdoch, 84, to Jerry Hall, 59.
The world has seen an equally measured response to Us magazine's reporting rumours last Thursday that Mr Murdoch's former wife Wendi Deng Murdoch, 47, is dating Mr Vladimir Putin, 63, the president of Russia who split from his wife of 30 years Lyudmila Putina in 2014.
It is no surprise that when French banker Olivier Sarkozy started dating Mary-Kate Olsen - the designer and former actress, who is now his wife and is 17 years younger and 33cm shorter than him - Mr Sarkozy's former wife Charlotte Sarkozy would say: "That's not right. It's grotesque."
But it is slightly bizarre when your otherwise hip and socially liberal friends make the same kind of comments, particularly when the couples in question are not on the child-producing or child-rearing path.
What is going on here? How is this any different from racism or homophobia?
"It's absolutely not different in almost all ways but one - it is tolerated in our society," said clinical psychologist Ben Michaelis.
"Unfortunately, when people don't understand certain other people, they tend to place them as an out group, psychologically. Then one of the ways they bring their psyches back into balance is to lower these out groups and the other way is to attack them."
Celebrity couples are, of course, particularly susceptible to this kind of scrutiny and biliousness.
Robin Dunbar, an anthropologist at Oxford University, said: "Celebrity-watching has to do with making sure the famous are not breaking the rules too much. We pay for them to be up there."
For some fans, it is even more personal. Ms Elaine Lui, a Canadian gossip maven and reporter for CTV's etalk and host of talk show The Social, said: "When a celebrity gets together with someone who fans perceive is not on his level, it's almost an insult.
"You're like, 'I cast you in this glorious light. If you pick someone who is close to me in status or looks, then why did I put you on a pedestal?'"
Thus the tabloids' fascination with lithe male actors and their zaftig, or conventionally shaped wives.
But when the couple is not famous, the motive behind the cattiness is less clear. Dunbar has written that gossip is often a form of social order, a way to cement bonds with your own tribe and to assert values with them. He said: "In most small-scale, traditional, hunter-gatherer societies, typically the word for your tribe is simply the word meaning human and anyone else belongs to a category that includes all the other animals."
Inappropriate comments are not necessarily derived from intolerance. Ms Victoria Binda, a teacher in New York City who is a white woman married to a black man, said that when they introduce themselves to new acquaintances, "almost everyone asks if we plan to make beautiful mixed babies since mixed babies are, as apparently decreed by some higher authority on infantile beauty, the most beautiful.
"My husband and I do not plan on having children, a decision that disappoints our audience and the human race. Some have suggested we're refusing to contribute to a better and more blended society."
But that is not the only thing on people's minds when they meet Ms Binda and her husband. "Many other women feel it's acceptable, even clever, to comment on our sexual relationship. They assume my husband is well-endowed and that we engage in a lot of wild extracurricular activities," she said.
Certain anxieties seem more justified than others. To be sure, uncharitable comments levelled at older men who repeatedly throw over their wives for increasingly age-inappropriate mates are of a different order from other kinds of deprecations, given the lack of originality on the part of these conquistador-husbands.
Ditto the instances in which one partner is very young - that playwright Eugene O'Neill disinherited his daughter Oona, after the 18- year-old married the 54-year-old Charlie Chaplin is understandable in the same way that the public's bafflement about Woody Allen taking up with Soon-Yi Previn was.
Snarky comments made about other unlikely alliances, however, often bespeak a callousness or a lack of esprit. When you marvel or jeer at the fact that one of the stars of TV's Nashville, the petite actress Hayden Panettiere, is with the hulking boxer Wladimir Klitschko - a man 40cm taller, 14 years older and unknown tons heavier than she is - are you unintentionally asserting the values of your culture or are you broadcasting to the world the impoverished dimensions of your imagination?
Dunbar, the Oxford anthropologist, said: "I suppose the question is, 'Which is more surprising, Rupert Murdoch marrying Jerry Hall or if Jerry Hall married a 20-year-old?'
"One look at Rupert Murdoch, you shake your head and think, 'What on earth is Jerry Hall thinking?' But if it were the other way around, you'd be absolutely astounded."
Many would. But to be so would be to make the world a smaller and meaner place. A place where the paradigm of romance and love is the crowded and smelly Noah's Ark. A place where, ultimately, the joke may be on you.
"I'll look at a couple walking down the street and think, 'He's on his third marriage and she's a gold digger,'" Ms Lui said.
"But even if that were true, she's getting hers and he's getting his. Sure, I'm being mean about it, but I'm the only person being hurt by it because I'm not getting mine."
NEW YORK TIMES