My favorite thing about Halloween is getting to wear some ridiculous or cliched costume out in public while everyone else does the same thing. I've seen people come up with some ridiculously clever things and some ridiculously cute things. Now I obviously know that many girls tend to wear skimpy, revealing things but I also know that people tend to judge them for it. Saying that girls just use Halloween as an excuse to dress like a slut is not only incorrect, but rude and ignorant as hell.
The thing about saying a girl looks like a slut is that there's no point in it. Slut shaming does nothing except try to devalue girls and make the person slut shaming feel superior and look stupid. Every girl has the right to dress how they want, whenever they want, and they should not be sexualized and shamed for their bodies or how they choose to show them.
I'm not saying I've never called someone a slut, because I have done my fair share of slut shaming. The difference is that I've realized that it's ridiculous and wrong and that I should not be against other girls, I should be on their side. There are already enough people judging us for our bodies and choices and I should not contribute to the problem that is constantly affecting me.
The thing is, girls should be able to do whatever the hell they want with themselves and their clothes. Who cares if some girl dresses in a decorated bra and shorts as a costume? She has every right to and it's not like it affects anybody else anyway. If that's what she wants to do, she shouldn't have to explain herself to anybody. If someone doesn't like it, that's their own problem.
Whether you want to wear something that covers your body or one that shows your stomach and legs, it shouldn't matter. It doesn't matter. Do what you will and ignore anyone who says you're wrong either way.