What do you mean you're going to get your ass kicked? Literally? People don't get their ass kicked at nerd conventions. I thought everyone just walks around in their costumes, plays gigantic RPG made out of actual stuff, and generally makes it clear (for most participants) how little they actually get out in life.
I think your costume rocks. It's like you're still with the spirit of the thing, and making shit out of the thing at the same time. A veritable walking contradiction. People won't know what to think of it.
PS - based on the descriptions I've been given, most chics at nerd conventions are uber-skanks. Those two, while probably not the kind of female you bring home to mom, look like they are at least two nights worth of fun. Especially together. $100 to the first nerd who can take a candid nude or partial nude of her and post it here.