Even their famous Nordic blonde hair wasn't always natural: Vikings were pioneers in seafaring, axe-murdering, and cosmetology alike, and their lightly colored manes and beards were often the product of bleaching. This practice also had a practical element: For several months of the year, everyone's bathtub was literally a block of ice, so bleaching one's hair and beard (and regularly combing them) kept lice and other unhygienic elements at bay. Don't think for a second there wasn't a beauty element involved, though. Vikings were totally all about lookin' fine: Even their most legendary kings were saddled with nicknames such as Harald the Fairhair instead of the more common but less awesome kingly monikers like "Great" or "Magnificent."
From the standpoint of a modern "Vikings were brutal barbarians" view, the end result of all this grooming, plaiting, and (presumably) nose-hair plucking was surprising: When they were not actively pillaging and raping, Vikings were actually quite a hit with the ladies all over the place, because they were just so goddamn fabulous.
Which makes everyone's Loki boners historically accurate boners.