Unisex perfumes have been around since women first swiped their boyfriends’ Canoe. But the idea was all but lost in the ’80s, when scents were as distinct – and overbearing – as the power suits. The lighter, more citrusy scents of the ’90s are intended to appeal to either sex, or both. Perhaps it’s an extension of the fitness craze – the couple who can stand each other’s sweat surely can stand each other’s cologne. But psychologist Robert A. Baron of Rensselaer Polytech Institute says it’s even simpler: “We’ve tested large numbers of fragrances,” Baron says, “and don’t find any major sex differences in things people like.”

Italian Greek jeweler Bvlgari helped start the unisex deluge with Eau Parfumee a year ago. The French fashion house of Hermes has one, and ever-savvy Ralph Lauren is repositioning the men’s cologne Polo Sport as a unisex “fitness fragrance.” And this week Calvin Klein gives his mighty imprimatur to the trend with his first unisex fragrance, packaged like a flask of vodka and named, simply, cK one.

Conjuring something men and women will wear is a matter of changing the sell as well as the scent. “The fairy-tale telling of the story is gone,” says Camille McDonald, senior vice president of marketing for Ralph Lauren Fragrances. CK one’s ads feature dozens of models slouching around in jeans, sending a message that’s less about passion than, well, smelling like one of the gang. You can’t get more unisex than that.