Fancy dress frenzy

Fancy dress parties are my favourite kind of party. My only problem is that I have to stagger the Pandora costumes with the 'Bob' costumes as I'm not 100% out.

I've got possibly two parties coming up in the next month, but I have a dilemma as they will be with the same peeps, so I cant wear the same outfit.

I've got a "naughty schoolgirl" outfit pieced together from real clothes which is my backup plan for the first party. I also just bought this:
The problem is that the second party might be Moulin Rouge themed, so I want to save the new costume if the second theme goes ahead. But I wont know that until possibly after the first party. *sigh*

I think its going to be a last minute decision. Unless I can get the organiser to commit to a theme now...