Since "big knickers" queen Bridget Jones and Y-fronts-clad Charlie's Angel Cameron Diaz popularised the look, we've seen larger, high-waisted underwear flaunted on the catwalk, the red carpet and the beach, as well as in the faux-casual bedroom selfies beloved of the Instagram generation.
"Traditionally underwear are foundation garments which means they are required to provide the structure and support of the outerwear layers," designer Nikki McAllum from The Road told news.com.au. "We seem to have lost sight of this over the years as pretty fashion lingerie is more easily marketed to a less than enlightened consumer.
"Ultimately, underwear should be comfortable which means it won't ride up or dig in and should be made from soft, breathable, preferably natural fibre."
New Zealand brand Lonely launched in 2009 with a revolutionary motto: "No padding, no push ups, no thongs." The styles are intended to "celebrate the strength and individuality of women" as well as fostering positive body image and freedom of expression. This is underwear for women, not men.
"Unfortunately 'granny undies' have been given a bum wrap," says news.com.au style commentator Melissa Hoyer. "Without all the mad puns that are going on about them, mine included, the stark reality is that larger undies are just more bloody comfortable than anything else.
"Sure, there are times when any woman may want to whip out something a bit smaller, more delicate and dainty, but for god's sake, I reckon we all go the grannies for comfort and complete ease. They certainly beat the muffin-top situ."
The shift in undergarment fashion has been attributed to the increased popularity of vintage high-waisted pants and skirts, as well as to feminism pushing to put comfort and ease of movement first. It is more inclusive of different body types, since it harks back to a time of hourglass figures - and can smooth out a woman's shape.
Khloe Kardashian recently mocked sister Kourtney for wearing "granny panties" under her activewear, but model sibling, Kendall, has regularly posted photos of herself in Calvin Klein underwear, as the comfy cotton 90s style roars back into fashion.
"Granny" undies also make the perfect loungewear at a time when the line between sleepwear and high fashion blurs, with women wearing pyjamas with heels out for cocktails.
The trend for tiny hotpants, adopted by Kylie Minogue and Sarah Jessica Parker, has morphed into simply wearing big underwear on its own, with singers like Beyonce regularly performing in just a large pair of undies and stars simply throwing a sheer skirt over the top for the red carpet.
At Mercedes-Benz Fashion Week in Sydney back in May, designer Steven Khalil told news.com.au: "We showcase the dresses with a naked look, but a lot of the time they will have a boy short on underneath. It's that exposure of skin, surreal and light that's the whole feeling of the look."
Stars from singer Taylor Swift to Channel 7 host Edwina Bartholemew have had their skirts fly up to reveal oversized underwear - and it's not even something to hide any more.
It would now be more surprising to see a star in a tiny G-string.
Granny undies are the way forward, and Sam Armytage isn't the only one who knows it.
