![Jump to it for the latest in high-fashion comfort - OnePiece - Sportswear](/images/20/07/b56950c3f19255765057b9c262bba92d.jpg)
The OnePiece, which launches in the UK next month, could be the love-child of last year's home-comfort hit, the slanket (sleeved blanket) and an Elie Saab S/S '11 flowing wide-legged jumpsuit — perhaps with a bit of a paternity challenge from Juicy Couture's Noughties-era joggers.
![Jump to it for the latest in high-fashion comfort - OnePiece - Sportswear](/images/20/07/fc87abb574c8511083fd14fa55374172.jpg)
![Jump to it for the latest in high-fashion comfort - OnePiece - Sportswear](/images/20/07/9950c941cd6b4a96ee2248c2ae725695.jpg)
It is, quite simply, an all-in-one tracksuit with a zip right from the crotch to the crown. They will cost you £80-£110 (from onepiece.co.uk) depending on the design you choose (from stars and stripes to two-tone) and, I can tell you from experience of my dashing purple one, they're darned cosy. Once I put it on last night, I was happy to stay swaddled all evening, knowing I was fitting in nicely with the current adult-sleepover trend — made fashionable by Soho House, Miami, which has been hosting exclusive celeb sleepovers since its recent opening.
![Jump to it for the latest in high-fashion comfort - OnePiece - Sportswear](/images/20/07/d623d11c30b9ff8a08100b48b83ac02d.jpg)
![Jump to it for the latest in high-fashion comfort - OnePiece - Sportswear](/images/20/07/03fce8e39058a907b1b06aaee9492cd5.jpg)
Clothing akin to an adult babygro may seem an odd choice to some but Sadie Frost has already declared herself a huge OnePiece fan — I can picture them being worn all over Chelsea, coupled with a pair of Jimmy Choo Ugg boots.