I think the brown one might be a bit too sexy for a wedding. If you're curvy at all, I think it has the potential to look like something Kim Kardashian would wear. If you're not very curvy, it could work. I think the one cahabo posted is a bit more wedding appropriate.
I think it is pretty and it would look nice if the reception is more on the dressy side. You could also look for a cute shrug to downplay the sexy factor if you are worried about it. As for color, my vote is for the purple: LOVE IT!
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Its a Long Island wedding - at the Swan Club (they literally have a little lake filled with swans outside). Its pretty swanky. I think I would def do a wrap but now you guys have me thinking about getting it at all! Do you think the satin would pick up every lump and bump from behind?