Puppy dogs are cute, adorable and entertaining ... but would you want to be in a romantic relationship with one? When Kelly Brook was in a relationship with Danny Cipriani, who was eight years her junior, she made the curious analogy, likening her boyfriend to a pet puppy.
"They make mistakes and do silly things, and you have to love them unconditionally and understand that they are young and learning," she said in 2013. Yet Brook could see the flipside of the coin, too: "It's a nice ego boost that someone in their 20s is attracted to you when you're 30," she says. "You hit 30 and you're like, 'Oh, I've got a nice young toy boy!' It's fabulous."
Kelly wasn't the only one to fall prey to the siren song of the toyboy's lure. Cooped up in marital bliss with Jamie Hince for several years, Kate Moss swapped out the 40-something Hince for a 28-year-old artist.
Count Nikolai Von Bismarck is the young, dashing son of Kate's longtime pal Countess Debonnaire von Bismarck. The pair have made a curious sight on the FROW at fashion week: she, the elder stateswoman of style, and he, the skinny, unassuming youngster on her arm.
No one was remotely surprised when 'MossMarck' were reported as being no more, but then Kate isn't really one for convention. While friends have said that she is 'back to her best' after splitting from the It boy, it now transpires that Moss may well have swapped her toyboy for an even younger version.
That alleged glint in her eye can be attributed, say some, to reports of a dalliance with 18-year-old Jake Curtis. Curtis is the privately-educated son of film producer Richard Curtis and former TV presenter Emma Freud, and Moss's links with Jake's maternal family have long been established.
Previously, Kate was linked to the late painter Lucian Freud, Jake's great uncle, 15 years ago, after she posed nude for him while she was pregnant with her daughter, Lila Grace.
The work, which sold for over €5million, took nine months, with sittings reportedly every day. The model, who was 28 to his 80 at the time, said: "Couldn't say no to Lucian. Very persuasive."
Only time will tell if Jake - a man at the very outset of his romantic life - will go the distance with 42-year-old Moss, but even if the relationship goes the way of Kelly Brook's with Cipriani, one thing's for sure… there's little denying the evergreen appeal of a toy boy.
Courteney Cox, Sam Taylor-Wood, Kris Jenner, Madonna, Jennifer Lopez, Mariah Carey - they've all enjoyed the regenerative powers of a man several years their junior.
Sam Taylor-Wood (48) and Aaron Taylor Johnson (25) are a particularly good example of when a relationship of this kind goes right: both are - according to received wisdom - slap bang in the middle of their respective sexual peaks, but are also dedicated, loving parents to two young daughters. (Also worth pointing out: decidedly fewer eyebrows were raised when Taylor-Wood's ex-husband Jay Jopling, then 43, enjoyed a romance with Lily Allen, aged 23 at the time).
And even us civilians get in on the act from time to time. I, too, can attest to the intoxicating, enlivening thrill of a relationship with a younger man.
Some years ago, I found myself in a casual relationship with a man nine years my junior: 21 to my 30. Start to look at those numbers a little closely and things don't look so great: when I was a jaded 20-something, he was a 12-year-old. Eek!
In many ways, the older woman/younger man is a fine match. Picture in your mind's eye a 'cougar', and you're not likely to see Ovaltine and a hairnet. Rather, cougars conjure up images of sexually molten, confident women. It's one stereotype few women would have a problem with, present company included.
Sure enough, older women find that sex with younger men is indeed intoxicating. Given that younger men have been raised on the teat of readily available online porn, this of course can be a blessing and curse. Younger men have an appetite for kink and quirk that will often out-colour their older lover's… but 'porn educated' men have their own problems.
Still, as Kelly Brook attests, the ego boost derived from dating younger men is rather delicious. Younger men have an enthusiasm for life and its myriad possibilities that their older male counterparts simply can't match. They're not jaded or bored with decades of hangovers; in fact, many young men are only starting out on their Byzantine path of misadventure. Who wouldn't want to be there for all of that?
But the novelty of a toy boy can wear off, especially if he's not house-trained. The cracks soon begin to show, and that's when it becomes a make or break situation (in my instance, break).
Sometimes, issues cannot be overcome: Courtney Cox and Johnny McDaid found that 'trust and power plays' were the rot that temporarily set into their romance: their engagement was called off briefly as the two couldn't decide where to live and neither was budging on the issue. The two have reunited, but will reportedly attempt a long-distance romance for now while the stand-off continues.
In some instances, the differing lifestyles don't tally. Adding insult to injury, the gulf in earning power causes its own frictions and difficulties. Wanting to be wined, dined and yachted? You'll be waiting. And I mean, years.
If, as psychologists attest, women develop at a faster rate than men (in every sense: financially, emotionally, psychologically) surely the chasm between the older woman and younger man is even greater still? It would certainly explain why no one seems to have too much of a problem when older men date women significantly younger than them.
So can these relationships work? David Kavanagh, relationship counsellor and author of Love Rewired: Using Your Brain To Mend Your Heart, says it depends on factors other than age.
"The relationships that work are those with good compatibility," he says. "Some people can be aligned in age but have such different value systems, for instance, that this is where the challenge is.
"Take Cheryl Cole and Liam from One Direction: they may have the same sort of lifestyle, but it's not likely they will share the same vocabulary around relationships, or understanding what love means. That said, if you're 65 and you're dating a 55-year-old man, you could be in the same maturity bracket.
"In terms of basic conversations between a couple, this is where problems can begin in relationships between older women and younger men. If a woman is able to communicate her thoughts and feelings quite well, she can be frustrated after the initial phase of lust and chemistry. After the sexual novelty wears off, she will find that his personality often doesn't add up."
Ultimately, the lure of the toy boy is, on the surface, great. But like any relationship, it takes shared values, agreement on big issues (like starting families or work ethics) and a core commonality to make a romance last. A romance with a toyboy, certainly, has been given the very helpful push in the right direction by passion and novelty. But as Kate, Courteney and Kelly would readily attest, all that youthful passion and virility ultimately comes at a price.