I know it's not a romance mod, but thinking from what your saying, anything is possible.
Viconia, I don't see her having any problem with it, at times during her conversation about her brother, she showed that she deeply cared about him. (Plus I would not put anything pass a Drow)
Aerie on the other hand I would see having a problem with the PC flirting with his half-sister.
Take care and hope I don't start a whole mess with this question.
