Left: Ronaldo’s CR7 tighty whities. Right: Beckham Bodywear for H&MGents, the fight for the bulging men’s underpants market, worth an eye-watering £700m, has begun. In one corner, the Portuguese striker Cristiano Ronaldo and his new brand, CR7, a collection of tighty whities and brightly coloured boxers; in the other, David Beckham and his range for the high-street giant H&M. This is Y-front war — and social media is the H-bomb. Guy Ritchie’s video of Beckham jumping over cars and running through people’s back gardens, bouncing around in a pair of stretchy trunks, went viral when it was released earlier this year. It has had 10m views on YouTube. Ronaldo countered last month with his own saucy short, showing the tanned-as-a-teapot metrosexual parading about in a pair of high-cut briefs. Ronaldo sent it to his 22m-plus Twitter followers — and much whooping followed. So who’s peddling the superior undercracker? In the name of hard-working journalism, I have selflessly road-tested both and can confirm that while Beckham’s well-cut, cargo-handling underpinnings are very good indeed — marvellous for tackling the cross-trainer and rifling through the smashed-tins section in Tesco — Ronaldo’s stretchy trunks (I’m more of a Y-front fan) were absolutely marvellous. I’d even go as far as to say I didn’t know I had them on, which is probably a good thing, but maybe not. My only concern is the design. They’re a bit, well, Peter Stringfellow — just a bit too sexy. And there’s more on the way. The Essex-born model David Gandy, who gained fame as the, er, face (read, packet) of Dolce & Gabbana’s sexy ad campaigns, is hoping to cash in on the hunger for elasticated designer waistbands with his own range. Men’s underwear is booming. At John Lewis, sales of underpants are up 20% year on year. “It’s an easier way of owning a designer brand,” says Ed Kelleher, assistant buyer for men’s accessories at the store. “Men used to buy pants for function; now it’s fashion.” Earlier this year, Selfridges Oxford Street installed a huge pants wall, stocking the largest selection of men’s underwear in Britain. Sales have increased by 30% since last year. “Men are shopping for brightly patterned pants,” says Jeevan Singh, the store’s underwear buyer. “Some men even want pants that add a little more enhancement.” Over at M&S, the home of t he nation’s smalls (one in five men wear a pair from here), trunks have finally usurped the Y-front as the pants of choice. The stretchy briefs now represent about 25% of the store’s total underwear sales. So, what makes the perfect pants? “Butt lift,” says Stefano Gabbana of Dolce & Gabbana. “And stretch — done properly. It’s underpant science.” Blimey. The nation can look forward to a far perter derrière this Christmas.