Glow-in-the-dark underwear (for adults) is happening thanks to Swedish fashion label Björn Borg, owned by the mid-'70s to '80s Swedish tennis landmark/class act of the same name. The company known for making sporty briefs in loud, colorful prints has launched a "Turning the Lights Off" theme collection that features luminescent details around the waistband and patterns with light bulbs, batteries, and soda cans. The brand hopes with these designs that the environmentally conscious wearer burns and saves energy simultaneously in the bedroom. No reason not to, right? To celebrate the cheeky undergarments Borg hosted an all-out rager to kick off London Fashion Week. There were saunas, hot tubs, models chasing each other in lit-up skivvies, Swedish meatballs, and a performance by I Heart Coco (Sting's androgynously dressed daughter Coco Sumner) with dance-pop extra-terrestrial Robyn.