On shore leave Hux goads people in a bar into trying to attack him so he can watch Kylo gleefully beat seven shades of shit out of them while he sits back and watches, laughing and drinking his stupidly expensive Space Mouton-Rothschild claret or whatever.

Afterwards Hux dismissively tosses a bag of credits at the cowering bartender, gives Kylo a chaste Kiss and calmly leads him out by the hand past the bodies and whatever terrified patrons are left.

Bonus!
+ they're technically in cognito so Kylo is not allowed to been seen using the Force
+++ Hux proudly sitting there with his legs splayed and his hard cock tenting his trousers, not even trying to hide how aroused he gets from watching Kylo beat people bloody for him
+++++ the fight gets really gory. like, Kylo is glassing people in the face, breaking their limbs with such force that bones are bursting through skin, biting a large chunk out of an arm that tries to get around his neck and blood spurts out to coat his face...
++++++++ rough, enthusiastic, blood-slicked sex with Kylo topping