every companion seems to think that the PC is a valid romantic partner
I wonder where did you get that impression.
Astarion offered you a night of "fun" ... no "romantic partnership" included there. O_o
Lae'zel decided to "reward you with pleaasure" ... no "romantic partnership" included there. O_o
Wyll calls you a good friend, and if you ask him if you are "just friend", he answers "yes" ... once again no "romantic partnership" included there. O_o More like friends with benefits in this case.
Gale and Shadowheart seems a little different, that is true ... but that is hardly every companion.
(Didnt seen Gale myself yet, he is quite slippery fish to catch.)
