Durge is the BEST character to romance Astarion, in my opinion. I'm assuming that they have these little interactions because they share the same writer (Stephen Rooney). It is wonderfully written.
But you're right spawn/DU relationship is so sweet. It seems that Astarion found someone who is even more broken than himself. Someone who [I quote] "gives him something to care for". It is nice to see that soft and caring side of Astarion under all that luster of his pretend persona.
After doing DUrge and romancing Astarion, I see no point in playing plain Tav. You get so much more depth in his romance with DU. I wish I didn't waste all that time on 3 playthrough playing Tav...
If they would just fix the ending now, that will be great. But I think the ending is bad in general.
