How do you explain the unprecedented success of a trilogy of mommy porn: soft porn aimed at and read by, predominantly, women? In a word: Play.

The 50 Shades of Grey books have so far sold 10 million copies in 37 countries. These books nurture and free our inner goddess (to borrow the lead's alter ego) to consider the possibilities. What if we could put the play back into playing around? And perhaps more importantly, what if the players took their roles more seriously?

The leads, Anastasia Steele and Christian Grey (haute-romance monikers if I ever heard them) know how to play in the bedroom, the "play room," the elevator, the car, the boat, the plane and the meadow. Their sex life is imaginative and vivid. They know how to flirt, how to tease, how to get their way. And, oh, it is amusing and oh, it is fun, and oh, it is filled with oh, oh, oh.

OK, this isn't high literature. But I don't imagine that was the author's intent. It's a romantically charged erotic fantasy. Christian? Ah, he's the quintessential romantic hero: tortured and twisted and wildly handsome. Plus he's a billionaire. And he's in lust, er, love with Anastasia. And she's going to fix him (good luck with that!). They have sex at least twice daily, which can't last -- at least not in real life. Their obsessive-compulsive relationship isn't healthy, or realistic. But verisimilitude isn't important; what's important is fueling our romantic fantasies.

The erotica totters on its spike heels toward S&M, but never arrives; this is not the Story of O (by Pauline Rèage). Rather, the dominant/submissive model is Christian's preferred modus operandi. He even provides his subs with a contract replete with safe words so they can escape if the activities prove overwhelming.

Anastasia doesn't sign, but she does agree to play around... and she has a lot of fun, mostly because Christian is a hot lover. He knows what to do and where and how (without being asked) -- plus he's uber romantic: flooding boat houses with flowers, obsessively worrying about what she's feeling and thinking, flying across the country to see her, endlessly email-flirting. This is a rollicking fun read, which, by some reports, is stimulating people's love life.

There are certainly lessons to be gleaned: lessons in how to flirt, and how to withhold pleasure (to maximize pleasure). There are lessons about how to fight, and the fun of make-up sex. There are also lessons about how to ask for what you want (even if it is a spanking!) and how to make sex playful.

Admittedly, these shenanigans could intimidate some couples, but judging by most media reports, the effect has been just the opposite. Women find the books are sparking their libido (the sex scenes are very graphic) and men are loving that. Google it and you'll see what I mean. I heard a female caller to a May 30, 2012 CBC radio show remarking that "a friend said it changed her sexual life, doing things she wouldn't do. It's definitely done the same for me." And a male caller said: "It's been a distraction. I see things from a different point of view; I aspire to be a better lover."

Now that's sexy.

The above is written by Barbara Sibbald's psychologist persona in The Book of Love: Guidance in Affairs of the Heart, a self-help novel.