Celebs are famous for it, there are websites devoted to it, and the media can't get enough of it. The phenomenon of older women dating younger men seems to have exploded in recent years. But why?
"I don't think age matters as much as it used to," says Jacqueline Hellyer. The sex and relationship therapist should know her partner is 10 years her junior.
"I think it's largely due to the status of women. In the old days women had no power and no money. They chose to marry someone who could look after them and that was usually an older, well-established man," she says.
But times are changing and most of us now marry for love rather than money.
"Finance is not such a consideration anymore," says Hellyer. "Women can be successful at work and earn their own money. They no longer have to marry someone to provide it for them."
Figures from the Australian Bureau of Statistics show how society has changed. There has been a steady increase in first marriages between older women and younger men since 1974. Between 1996 and 2006 the proportion of women in a relationship with someone more than 10 years their junior rose by 23 percent.
In Hollywood, the trend is also growing. Madonna always has a young squeeze on her arm. Her ex-husband Guy Ritchie was 10 years younger, and the 53-year-old singer is currently dating 24-year-old Brahim Zaibat. Susan Sarandon, 65, is with Jonathan Bricklin, 35, while Hugh Jackman is happily married to Debora-Lee Furness, who is 12 years his senior.
"People keep trying to explain why older women are dating younger men. But it's easy to see why," says Hellyer. "Society has opened up. We have more social freedom now and can do things that weren't permitted or possible before."
More of us are also re-marrying, or re-partnering later in life, so there are more older women on the market.
So what's the appeal? Is it all about ego? She feels good for snagging someone younger, while he gains prestige from the Mrs Robinson effect?
"There is a certain element of ego involved as in any relationship," says Hellyer. "Why does anyone hook up with anyone? Because it makes them feel good about themselves. But it's more than that."
Online research reveals younger men like dating older women for a number of reasons: their sexual experience, confidence, successful career and independence. A study by online dating site www.whatsyourprice.com even showed some men just like the fact the woman is likely to pay for the date.
For women there are many reasons too. Some say younger men are more fun and come with less baggage. Others say they are more considerate and modern in their view of women's role in society.
Whatever the reason, so-called "May-December" relationships can and do work even if they're not what people are necessarily looking for.
"More often than not, such a relationship just happens," says Hellyer. "An older woman and a younger man get together because they like each other and society is becoming more accepting. It's as simple as that. Forty years ago cross-cultural relationships were frowned upon. Today, that's not the case. It's no different to that."