When Hux has some free time he composes and play his pieces with a flute/piano/whatever instrument exists in the Star Wars universe. He's evil and Kylo thinks he's insufferable but he has to admit, the General can create beautiful music.

+Hux's compositions are actually really famous and he signs them under a fake name so no one knows
+Hux playing something to Kylo to sooth him
+Hux also making Evil Music à la Imperial March and playing it like he's Davy Jones
+Kylo hums along