Fashion may be quixotic, but there are some things you don’t argue with: Mrs Prada’s genius, Karl’s Edwardian collar preference and the stone cold rightness of Nova magazine. In a prescient editorial printed in January 1969 with the headline, “What are you trying to hide?” the mag declared that the only response to worrying that your underwear would be visible beneath your clothes was to turn a wardrobe vice into a virtue. “Show that you mean it,” it declared. “Don’t count on your underclothes not showing, choose them so if they do, it doesn’t matter.” Accompanied by a model shot and clothes credited to Woolworths – an arch styling move if ever there were one – it documented a pivotal moment in the fashion history of underwear as outerwear.

Forty-five years later and the concept of the blurred line between public and private fashion – what ought to be concealed or revealed – is still being played out on the catwalk. For spring 2016, the debate began in September at the Givenchy show – a visiting dignitary at New York fashion week for one season only – where designer Riccardo Tisci riffed on a slip dress theme with chemises, wispy lace and silk slips. At Calvin Klein, creamy ankle-length slip dresses with misbehaving slovenly-cum-sexy straps were worn with minimal trainers and recalled the 90s. It was an echo of the brand’s heyday, a moment of nostalgia for those whose love affair with fashion began when a doe-like Kate Moss defined the brand. In London, Burberry continued the theme, showing silky flowing slip dresses with utilitarian rucksacks and contrasting chunky sandals. Was Christopher Bailey submitting to his inner grunge rocker?

As you might expect, the underwear-on-display look was especially prominent in Paris, spiritual home of the cinq à sept. Alexander Wang’s swan song at Balenciaga was filled with tryst-worthy clothes, all white silk nighties and hotel slippers, a romanticised room-service look. At Céline the trend crystalised. Phoebe Philo isn’t known for pushing overt sexiness, and her lace-trimmed slips with intentional creasing weren’t presented that way. But in the hands (sorry, on the boobs) of a woman with curves – as evidenced by Dakota Johnson on the cover of Vogue – their sensuality is hard to ignore.

But it was Hedi Slimane who really spelt it out, with a Saint Laurent finale celebrating grunge. Slip dresses with Courtney Love-worthy tiaras and explicitly bare backs that felt more backstage pass than boudoir summed up the allure: despite its flimsy fabric, a slip dress can multitask, representing both sex and rebellion at the same time.

A quick skirt through the history of the slip dress backs up this theory. Fans of the style include, in no particular order: Kate Moss, Michelle Pfeiffer’s Elvira Hancock in Scarface (come on, in fashion terms she is real), Elizabeth Taylor, Rihanna, Madonna, Drew Barrymore, Courtney Love, Veronica Lake and Princess Diana. Women who share, if not a style, then a kind of sartorial irreverence.

In its basic form the slip dress, with its spaghetti straps, silky fabric and often lacy trim, mirrors underwear, but also wants to be seen. Undressed: A Brief History Of Underwear, an exhibition opening in April at London’s V&A, examines the relationship between underwear and fashion. Its curator, Edwina Ehrman, sums up the wearing of underwear as outerwear as “a way of challenging contemporary morality. It represents the difference between what should be public and what should be hidden, and the breaking down of those barriers.”

As far back as the late 18th century, fashion leaders such as the Duchess of Devonshire and Marie Antoinette were wearing fine muslin dresses with a sash around the waist. Not so shocking now, but to their contemporaries it would have looked as if they were wearing their underwear. Ehrman claims that the classic Jane Austen-style dresses of the early 1800s were an even earlier example of this. To underline her point, the curator has chosen to exhibit a Pride And Prejudice-type dress next to her own favourite underwear as outerwear dress: a John Galliano for Givenchy slip, cut on the bias and owing much to the 1930s slip dress trend. A newly single Princess Diana wore another Galliano dress – this one for Dior – to the Met Ball in 1996 just a few months after her divorce. Bet she was feeling sexy and rebellious that night.

For Bay Garnett, contributing fashion editor at Vogue and slip dress styling aficionado, it all depends on context. “You can have such different perceptions of the slip dress – in a tacky situation it looks terrible, but it can look incredible, too. Either East Hampton or totally grunge. To me the appeal is to deconstruct the sexiness, to subvert it. The genius of Courtney Love in a slip dress was that she turned an essentially conservative and conventional item on its head. It’s the ultimate punk thing to lampoon something so commercial.”

Like many, the slip dress that most resonates with me belonged to Kate Moss in 1993. Wearing a transparent silver slip by Liza Bruce to a model agency party, Moss accessorised with an almost empty beer bottle and a Marlboro Light. The dress hides nothing and highlights what look like knickers from a multipack of pants. What is shocking is not that you can see the moles on her breasts but just how nonchalant she is about the whole thing. It’s a display of pure casual rebellion. Ehrman, who has included the original Bruce dress in the exhibition, agrees that the moment was “so natural, like she’s just pulled it on”.

In today’s post-Kimoji age, where catwalks are live-streamed on Grindr and naked penises swing on the runway, the idea that underwear as outerwear might shock seems almost quaint. So what is the appeal of the slip dress now? Overt sexiness is not the prevailing mood in fashion, but we are enjoying yet another 90s revival. From Christopher Kane and Vetements’ grown-up grunge to the minimalism of brands such as the Row and Joseph, the style imprint of that decade is hard to ignore. The slip dress is mercurial in this context – it can be a grunge-worthy charity shop find, sleek and minimal, or sexy, depending on your shoes and hair.

Add in a trim of lace, known among high-end fashion buyers as “retail gold”, and the slip dress represents the perfect fashion storm. It pushes style boundaries and cash registers in a louche, dishevelled way. It speaks of punk and grunge and sex – but all in the most casual fashion.