Prom bras and corsettes?

If strapless bras don't work for you and you're going for slimming your stomach then a corset is your answer. They sell them at Victoria's Secret where you can get fitted so you get the precise size. Otherwise get fitted at VS anyways (it's free) and make sure to tell them you're looking at sizing for a corset. Then you can choose your size and the right color (just in case any shows by accident) for your dress and skin tone. Make sure it's high quality as well, you want to be able to wear it over and over.