I have been ridiculed for my gigantic £42 'adult sippy cup'. But I'm gulping more water than ever. This is why I am a fully signed-up member of the Stanley Squad along with Adele, Victoria Beckham and Meghan

Adele can’t do without hers. Victoria Beckham and Meghan Markle have been pictured out and about with them, while Jessica Alba has shown off her baby-blue version on social media.

If you think the must-have item in question is a Hermes Birkin or the latest Chanel crossbody, I’m afraid you’re a decade behind.

For the latest craze among celebrities and on social media is not a designer bag. It’s a supersized, insulated water tumbler. These almost comically gigantic ‘adult sippy cups’ have become ubiquitous at boutique gyms – a signifier for anyone who identifies as a oh-so healthy, Lululemon wearing, salad-eating Pilates fan.

While the colossal cups come from various makers, such as brands like Yeti (Victoria Beckham’s preferred model) or Simple Modern (Meghan’s favourite), the current king of water bottles is the Stanley ‘Quencher’ – a ginormous, £42, 40oz (850ml) mug with a straw.

Mail journalist Clara Gaspar says she is a devotee of the Stanley ‘Quencher’. The cup taking the internet by storm. ‘I’m gulping more water than I’ve ever done before,’ she writes

Comedian James Corden helps British singer Adele to a drink from her Stanley cup while she’s behind the wheel during an episode of Carpool Karaoke

Victoria Beckham is spotted using one of the viral cups to help stay hydrated while on holiday

The hashtag #Stanleycup now has over seven billion views on TikTok and a cult-like following online with celebrities including actress Shay Mitchell and Love Islander Molly Mae Hague evangelising about it. They come in dozens of different colours, each selling out within minutes of release.

Just last week, Stanley sent social media into overdrive with a much-anticipated, limited-edition collaboration with Starbucks for Valentine’s Day.

Videos emerged of shoppers in America queuing overnight to get their hands on the bright, £35 pink and red cups. Viral footage even showed one man attempting to grab a box of them before getting tackled and beaten up by other customers who had queued for hours. The cups are now reselling for as much as £150 each on eBay.

So how did an insulated cup – which, let’s face it, was once the preserve of construction workers and mountaineering dads – become the ultimate fashion statement?

Ever since William Stanley Jr – not of the Stanley knife – invented the steel vacuum-sealed bottle in 1913, the Seattle company has sold various tumblers – from 14oz (400ml) to 64oz (1.8l), catering for long-distance drivers, outdoor workers, picnickers, hikers and more.

World War II pilots carried Stanleys onto their planes. As recently as 2012, Stanley said that its products resonated mainly with ‘a 30-year-career veteran policeman’ and ‘a retired Army soldier.’ It’s safe to say that Stanley fever didn’t take hold overnight.

It was only in 2016 when the company released their Quencher model that the brand caught the imagination of Gen Z – those born between the late 1990s and 2010. I must declare an interest here: at the start of the year, I succumbed to the TikTok-mania and purchased a Stanley cup.

Not the viral Quencher, but its leak-proof sister, the IceFlow – a 40oz bottle with a flip-up straw – for £42. I have been ridiculed for the purchase by colleagues, family and friends – but since first filling it over a week ago, I am beginning to understand the craze.

On TikTok, influencers began sharing how much water they carry in their tumbler and how it was keeping them ‘hydrated’. Pop queen and TikTok royalty Olivia Rodrigo sparked a new wave of devotees last year.

‘I was actually TikTok-influenced into buying this,’ Rodrigo said, cradling her lilac cup in an video interview with GQ.

‘I was like, “I need this. This looks like it will change my life.” And it completely did.’

Stanley’s revenue has soared – from $94 million in 2020 to $194 million in 2021, doubling again to $402 million in 2022.

Ostensibly, it is the practicality of the product that appeals. At the heart of the Stanley Tumbler’s popularity is its insulation technology that, I can testify, really does keep drinks hot or cold for up to 24 hours.

In November last year, TikTok user Danielle Marie Lettering proved this point to the extreme. She posted a video showing the aftermath of her car bursting into flames. Amid the charred debris of her burnt-out Kia, her copper-coloured Stanley sat completely intact in the driver’s seat cupholder, with ice still left frozen in the tumbler. The video now has over 94 million views. Clearly delighted with the marketing opportunity, when Stanley saw the video, the company offered to replace not only the cup, but her car.

The Duchess of Sussex, Meghan, appears in the background of a social media video enjoying a slurp from her own huge cups

American actress Olivia Wilde is seen out and about carrying her own drinking cup

The Stanley, however, is more than just for drinking; it’s a lifestyle statement. The hashtag #StanleyTumbler has become a gallery of adverts for the product, showcasing the tumblers in picturesque landscapes, cosy coffee nooks and vibrant cityscapes. It plays into the ‘boujee’ aesthetic, apparently. That’s a Gen Z term derived from ‘bourgeois’, which describes the trend of unashamedly displaying wealth and materialism on your online platforms.

Too skint to afford designer bags and sunglasses, young social media users compromise with a must-have branded water bottle.

Do they cut down on plastic waste? Stanley claims it is ‘reducing demand for disposable products that end up in waste and water streams’, but its Gen Z customers don’t see it that way. Instead, fanatics collect dozens of the flasks, matching their Stanley to their outfit on a given day.

And though it might look like a grassroots social-media trend, Stanley’s bosses know what they’re doing. In 2020, the company hired Terence Reilly as its new president. Reilly spent seven years at footwear brand Crocs, where he led the transformation that saw the ugly rubber clogs turn into one of the hottest shoes on the market.

Reilly saw opportunities in a burgeoning media landscape.

Gen Z is constantly looking for ways to turn the ugly ‘cool’ again. Reilly made it happen with Crocs, but the same phenomenon goes for absurdly baggy jeans and giant tote bags that are the uniform for ‘fashionable’ tweens – as well as the resurgence of once-nerdy Birkenstock sandals. So it’s no surprise that this demographic embraced the idea of a ‘sippy cup’ for adults.

Just as many young TikTok users advertise weighted blankets or collect soft toys as a means of staving off anxiety, sucking from the nipple of a giant flask can be oddly infantilising. The hashtag #emotionalsupportwaterbottle has more than 330million views.

So what do people put in their flask? Some suggest spiking their water with candy-flavoured powdered-drink mixes, fruity syrups or even plain old Coca-Cola. And I haven’t even mentioned the American influencers filling their flasks to the brim with litres of Caramel mocha frappuccinos or – Victoria Beckham, stop reading now! – hot chocolate.

Tragically, for water purists like me, this is disrupting the Pilates/salad ‘vibe’ of the Stanley.

As a result, some say the cups are on their way out. ‘This is peak Stanley. There’s no up from here,’ says youth consumer trends analyst Casey Lewis.

I’m not so sure. Though the water bottle has its faults – it’s bulky and the straw is difficult to clean – I’m gulping more water than I’ve ever done before and consider myself a fully signed up member to the ‘Stanley aesthetic’. That is, until TikTok tells me there’s another flask out there that’s even more cool.

Stanley, a brand which used to be the preserve of long-distance drivers, hikers and outdoor workers, has seen revenue soar since the cups have grasped the attention of youngsters

TikTok user Danielle Marie Lettering posted a video online of her car after it burst into flames. Amid the charred debris of her burnt-out Kia, her copper-coloured Stanley sat completely intact in the driver’s seat cupholder, with ice still left frozen inside