This summer’s latest trend might – off the body – look as demure as the cardigan, but this is not for the shy and retiring. Described as either the “curtain reveal top” or the “pin top”, the item is worn with nothing underneath. The two curtains of the top are held across the wearer’s breasts by a safety pin or a tiny piece of string.

Worn by models including Bella Hadid, Emily Ratajkowski and Hailey Bieber, and endorsed by Vogue, search platform Lyst reported that searches for these tops increased 78% in the last two weeks. After Megan Fox was spotted wearing a red cropped cardigan by French brand Jacquemus like this, searches for the item went up 52% in 48 hours, and when Ratajkowski wore the Cult Gaia pin top in June it sold out.

Curtain reveal tops are part of a wider trend in fashion for clothes that reveal breasts in ways beyond typical Wonderbra-style cleavage. If the Kardashians’ wearing bikini tops upside down was spotted on Instagram earlier this year, Love Island has brought this experimentation into living rooms nationwide. Contestants Millie Court and Faye Winter regularly wear open blazers and shirts without anything underneath and – presumably – strategically placed tape keeping their modesty intact, while so-called “underboob” swimwear is worn by all female contestants.

Hannah Banks-Walker, the fashion and beauty director at Grazia, wrote about the underboob swimwear. She suggests this is part of a bigger shift. “Fashion went through that period of shying away from anything that could be deemed remotely sexy and dresses became oversized,” she says. “I think now we’re definitely seeing a return to that sex appeal, unapologetically.”

While the statistics suggest ordinary young women are buying into the pin top trend, Banks-Walker is sceptical that all will embrace it. “It’s not exactly democratic,” she says. “It depends on how you feel but if you have bigger boobs and you want to wear a bra … those sort of tops are not really going to cut it.” She says the sexy look will continue though – with the bodysuit next up for autumn. “Obviously you’re not necessarily showing any skin because you’re covered from top to toe but it’s this new interpretation of sexiness which I thought was interesting.”