Hux is a military man but he's also the vainest man in the galaxy and thinks appearances are everything. He loves cosmetics and wearing expensive perfume, all his clothes are made with the best, most comfortable material...and Kylo would hate it if Hux didn't smell and looked that good. Cue Kylo being frustrated because he wants to punch Hux as much as he wants to see if Hux's skin is as soft as it looks.