To initiate a romance you'll first need Viconia in your party. You'll find her tied to a stake ready to be fried by a bunch of civilians in front of a jail in the... ~scratches head~ Eh, I THINK it's government district, don't take my word on that though. You'll find her talking to you, tell her what she wants to hear and it'll get farther and farther. Note she is an evil, and more importantly a drow, so you likely wouldn't romance her the same way you'd romance Aerie! Be sharp with her, but not to the point of calling her a bitch and you'll be fine.
------------------
"Eh? No, I don't hold grudges. Why? There's nothing to hold a grudge against, I kill what pisses me off!"