Why dress up as one when you can dress up as two this Halloween? The range of couples' costumes on the market naturally lend themselves to clever and often comical pairings. Like ketchup and mustard or Adam and Eve. And it doesn't hurt to think outside the box when dressing up with your partner or BFF. If that means dressing up as two halves of a peanut butter and jelly sandwich, well, so be it. It's time to become one with the Halloween decorations! Check out our pick of some of the silliest, sexiest and down right odd couple costumes for Halloween.