Well should I?
Well Bippy that depends on what the occasion is. Care to elaborate? Are we talking about a bedroom occasion. Are you going to be wearing 7 inch black heels? I need more info. 
And above all are you still going to be Beardless ?
Beardless, of course (if I don’t forget to shave anyway). Probably just Shopping round San Francisco if it don’t rain too bad this weekend.
I say go for it! But only if you take pictures so we can see. Deal? 
Wooo! Show us your legs! 
I think it depends on what the rest of your superhero costume looks like.
I’m going to agree with Bumbazine on this Bippy. Fishnet stockings with say, a Batman-esque costume are perfectly acceptable, but just wrong with a Spiderman-esque outfit. In part, the cape makes all the difference. Why, even Superman could wear fishnets while he’s got his cape on, but he’d look silly with out the cape.
But you also must consider the venue. You say you’ll going to be in San Francisco and even with the right costume, I’m thinking fishnet stockings might just be a little, well bluntly, so five minutes ago. Go with the classy look–a single seam in the back. Timeless, and it goes with everything. Just make sure they’re straight.