As a bit of a nudge and a wink for Valentines Day, Obsidian has decided to release a developer update showcasing how they plan to expand upon companion relationships in Pillars of Eternity II: Deadfire.
Obsidian's strong suit has always been their writing, and it looks like they're really weaving that strength into gameplay mechanics for Deadfire. Relationships in most games often hinge in key good-or-bad moral choices but in Deadfire relationships with your party members can develop through subtle actions. An example they give is if a particular party member has an affinity for animals, and you in turn are cruel to animals, your companion will develop a negative relationship towards you.
You should check out the full backer video below for a more detailed explanation on character relationships in Pillars of Eternity II: Deadfire!
Furthermore if you would still like to help back the game, their crowd funding page is available here.