I'm wondering if the curse might have an exception at this point since outside of chapter 0 which seems to be a "oneshot" kind of thing the story probably shifted in someway. Can't recall any hints toward the cause of the curse or clear suspect of the caster.
@kronix if they go at it ... we'd be looking at necrophilia in the worse case
So from my interpretation its basically saying that either the Duke gets cured, becomes the head of the family and marry a fellow noble (because of muh wealth or royal blood) or stay with Alice but never get to touch her.
If that's how things really are then I'd rather stay with option B