Passion other than anger can be used to fuel Dark side power. Hux assumes that Kylo's request memo for a squadron of Stormtroopers to conduct a gangbang is an attempt at humor, so he denies the troop request. Kylo storms in twenty minutes later and explains that he's training and needs sex, hate, and pain to push him past his limits.
Hux snaps that if Kylo wants to be flogged til he cries then fucked til he begs then he'd volunteer rather than waste troop resources.

TW - not safe, not sane, ultimately mimics violent rape, but consensual.

Link:
http://tfa-kink.dreamwidth.org/3467.html?thread=7367819#cmt7367819