The two of them are happy together. Kylo Ren watches.

Rey fights, pines, defeats some bad guys, pines some more, gets sex pollened, acquires parents, defeats some more bad guys, and lives. Especially the last bit.

Finn and Ben fit together.

Finn, a war hero and a Senator for the stormtroopers settled on Kef Bir, experiences an assassination attempt. The Senate, furious at Finn for insisting on stormtroopers' right to self-determination, assigns him a convict who's had his ability to access the Force stolen from him: Kylo Ren.

Then shit really starts getting weird.

When Finn and Kylo meet again, the world is falling down around them.