I know she'll probably not want to stay with Durge, given her commitment to Shar, but I wanted everyone to have their worst outcomes in this run (That survive). Lae'Zel is loyal to Vlaakith. Astarion is going to ascend. Minthara... is just kind of bloodthirsty as ever. Everyone else is dead. In truth I wish I had romanced Astarion because I hear that if he ascends you either get bit by him or he leaves/you have to kill him, which is some great drama, but whatever. It's way too late in the save to undo that now.
I also don't mind an 'unhappy' romance ending. My Durge is fully embracing himself as Bhaal's chosen, his intent is to murder eveyone else in the world and then himself. Any 'love' is strictly about pleasure. There was definitely something so diabolically messed up about the love scene after defiling Selune's statue with Aylin's blood that I definitely don't regret that.