So are you just talking about the spongy style flip flops, like toe goz, and rainbows and reefs?
My daughter's friend just bought an adorable pair of black flip flop style dressy sandals--they're leather, they have a small heel and look cute with a sundress. Would you consider something like this "flip flops" or "sandals"?
The only time my daughter wore flip flops with a dress was on bid night when they run for the roses. If you don't get to the front, you might not get a rose, so you don't want heels slowing you down!
