Well I am not sure that this qualifies as Quest failed... technically you did everything to complete it (otherwise the MC would have died after 3 days), but since you never took the reward (4-some) the last trigger was not set on complete.
Maybe Tinkerer will add an option for the 4-some to be had in the crypt of Castle Tepes at some point... you CAN have the sex scene from "A dress for a Lady" in the castle afterall (which plays in a crypt in the castle or the graveyard).
Same that he may add an option to Gift Zsofia the dress after relocating to Castle Tepes.
Currently Tinkerer adds more new stuff but eventually he'll have to adress these small things in order to make this game sandbox style again.
Currently you have to play the game in a certain way to get all sex scenes unlocked though.
I did have the 4-some its just never let me give the dress because of the hunters blocking the way once they came into the game up.
I never should have talked to Oksana when she first came to town because once I did I could not give the dress.
This is the part that needs to get to the dev to hold off on Oksana until the other quest are completed.
Or dev puts in an update so we can give the dress at there new home, other wise this quest is a failure and can not be completed.
Once talking to Oksana all I can do is warn the stupid vampires of it and no other option was there.
As you can see others are having the same problem that I got.