Kylo and Hux both keep switching sides. Maybe Kylo is easily swayed back and forth in the aftermath of Han's death, maybe Hux always just wants to be on whichever side seems to be winning, maybe they keep ending up on opposite sides and both try to switch to be with the other one, or the opposite where they keep ending up together and defecting to try to get away, they thought they were finally free.

I want them changing sides so often even they can't keep track of who they're betraying for which side now.

Absolute bonus points if they keep trying to 'take advantage' of the other one's totally not-requited, that would be ridiculous, so one-sided attraction by sleeping with him (for the mission) but by the end they can't even build a credible argument for why they are currently fucking.