They're not in relationship but they stay inclusive to each other, they just copulate when there's heat cycle and that's it. No feelings involve between them but we knows how much Kishiar loves Yuder in the past live but can't say (more like stubbornly wouldn't say) anything cause he's dying
Guys I dont mind spoilers but I have a question. Where ml and mc in a relationship in their previous lives or is it as yuder says?