Two summers after capris were a must-have for gals, the XY set is adopting the popular flood-warning look. The playful trousers, which bring to mind late golfer Payne Stewart’s trademark plus fours, are now elbowing aside boot-cuts and flares in the men’s section. ”This is an in-line-skating-inspired thing,” explains Amy Maniatis, PR director for Gap, which currently offers the style in traditional twill and Teflon-treated nylon. ”It goes back to skateboarders and skaters. The shorts got longer.” They’re also the perfect corrective for guys afflicted with chicken legs. ”It’s about comfort. They help men who find board shorts hard to wear,” says Stan Brooks, senior stylist at Diesel USA, whose version is a little more dude-ish. But the trend’s only, uh, 75 percent there. The funky HUGO Hugo Boss line will unveil a male twist on that sorority-girl staple, the three-quarter sleeve, in its fall collection. What will guys embrace next? Sweater sets?