diff.text: Due to the controversial nature of their relationship, Haruka and Michiru were introduced as cousins, a fact reinforced by others that technically should not have known to begin with. But despite that, their flirty banter is mostly kept intact throughout the season. 
diff.text: In the final season of Sailor Stars (which has yet to be dubbed and most likely never will), their relationship has stepped up a level from banter to almost explicitly physical in nature and no amount of dubbing would be able to change that. Part of the reason why Sailor Moon S took so long to come out was because the dubbers had to work hard to conceal their relationship.