I've been invited to a fancy dress party tomorrow night, which would be cool, if I wasn't stumped for ideas.

The theme is simply 'bad taste or inappropriate dress', but I am home from uni for a short while, so don't have the majority of my clothes/there aren't a great deal of places to get clothes in town. I was going to go in my normal clothes and say I was inappropriately dressed for the fancy dress theme, but that is a bit of a cop-out.

So any simple ideas would be greatly appreciated. The funnier the better. I will consider all options.