Poe's little prank call at the beginning of TLJ humiliated Hux in front of his subordinates, and Hux is not the type to forgive and forget.

When the Resistance is finally destroyed and the last surviving rebels have been captured, Hux actually sees Poe for the first time, and decides to take his revenge by making Poe his sex slave.

(I'm imagining a kind of Stockholm-y dynamic, and I'm also imagining Hux being very utilitarian about sex rather than engaging in any elaborate sexual torture or kinky slave training—but feel free to take the prompt in whatever direction you want!)