I have another thing to say about Halloween costumes. I'm with Dan that Halloween is essentially straight pride day, and humans should go with their sexy selves.
But I would also propose that if you are a person who finds yourself casting a judgmental eye at cleavage every other day BUT Halloween, you have no right to show yours on Halloween.
If I see your sexy on Halloween, I wanna see it at least some other days, too. And I don't want to hear your prudish bullshit the rest of the year. Unless prudish bullshit is, like, your kink.