This is a huge bug. If you have finished the main quest, your significant game other will only greet you with "friend" dialogue.
if at all, other than "Hello friend.", or "Well met.", and It's been this way since the game released. No matter what gender your
quizzy is, or your romance choice, they will always revert to "friend" status, after defeating Cor...what's his name...
which is really frustrating if you've been out hacking, slashing, frying, zapping, being a gopher, for another 100 or so errands for
everyone who is too lazy to go out and get that something themselves, and have been gone for a while, and want to have some
"quality" (or quantity) time with your partner... you can't even get them up to your private room in the castle.... grrrrrr
I have played through many times, with different quizzies, and with different romance choices, and it's always the same.