It’s not like they both sailed off into the twin sunset. Kylo got a satisfying kiss, sure, in return for saving Rey and in that moment of returning from death no less, excites overwhelming emotions.
By the end, neither enter a relationship and Rey retains her independent lifestyle. Not much harm. Only Luke and Leia are seen at the end to be cherished as family and no where is Kylo around to hint at some cosmic Force ghost, star crossed lovers nonsense.