How about a reversal of ‘Kylo-in-FO-uniform’? Kylo and Hux have an argument. Maybe Kylo accuses Hux of being so anal and uptight that he’d be unable to function if his uniform wasn’t perfectly pressed. Maybe he says Hux is getting boring in bed. Either way, Hux is pissed off enough to prove him wrong, He puts on Kylo’s spare robes, his cowl, his heavy boots. Cinches that wide belt around his narrow waist, Then he finds a place where Kylo is sure to find him.