Stanger's general rule of thumb for dating, regardless of who is on the winter end of the May-December romance, is "10 up, 10 down." If a couple is 11 years apart in age, she said, "don't cry. It's no big deal. But if you go 15, you're screwed." Stanger has also mentioned this notion on her reality show, "The Millionaire Matchmaker," which is in its sixth season on Bravo. On the series, she often takes on male and female clients who are looking for someone significantly younger than they are.
When that happens, Stanger added, cultural references are lost and one person assumes the caretaker role, which can be a problem when that person is the woman.
"When you do 15 years, when you do Demi Moore and Ashton Kutcher, it's going to run its course," she added. "It can't last when the woman is older than the man. When the man is older than the woman, unfortunately, there is a double standard and it does last. Especially in different cultures ... that is the norm because a man is supposed to provide and guide for his woman."
The puma and cougar debate also has a place among gay, lesbian, bisexual and transgender daters, though the lines are blurrier. When 26-year-old actress Amber Heard and 36-year-old photographer Tasya van Ree went public with their relationship in 2010, age wasn't at the forefront of reports the way it was for Carey and Cannon.
"Opinions on age difference run the gamut from fearful to desirable," author Dave Singleton wrote regarding the gay community in his Match.com column, "Ask Dave."
"There's no hard and fast rule on whether age differences sink the love boat," Singleton wrote. "But age is definitely a factor when you date someone. ... In my research with gay men for my book, 'The Mandates: 25 Real Rules for Successful Gay Dating,' I never met one who described a date without telling me the guy's age first."
As Schwyzer says, "The problem is largely cultural at this time. ... (There will be) jokes about robbing a cradle. The expectations are somehow that (a woman is) not capable of being with a grown man and has thus chosen to date someone who our society thinks of as a boy."
In October, London-based video blogger Emily Hartridge, 28, posted a video about the benefits of dating a younger man. The comedic vlog listed reasons such as "younger guys try harder to please you" and "you get to feel more in charge" among the perks.
Another plus for some career-driven, powerful women in their 20s and 30s, Schwyzer said, is that millennial men tend to be more open about gender roles.
"For decades women have moved into traditionally male spaces," he added. "With some millennial guys ... we're not seeing more guys who are feminine, but flexible."
For my friend, the best thing about dating a younger man -- at least her younger man -- is that there's no noticeable age difference at all.
I can pick on her all I want for dating someone the same age as my younger sister. And I'll probably continue to do so -- out of love, of course. But truth be told, there's less of a cultural gap between her and her younger beau than there was between my last boyfriend and me. At six years my senior, he was behind the wheel of a car while I was still riding around the neighborhood on my Razor scooter.
At least my "cougar" friend and her juvenile boyfriend can both recall growing up listening to cassette tapes, playing video games on the original PlayStation, and watching Bill Clinton deny that he had "sexual relations with that woman" -- even if one of them wasn't quite sure what that meant at the ripe old age of 6.