Reddit reviews Fashion First Aid Women's Low Expectations Low Back Bra Converters for Plunging Backless Dress Top, Adjustable (Small, Beige)

I think a strapless bra would work, or a multiway bra configured to be halter style for the sailor girl dress. I don't know how well it will work, but these things can be used to make your band lower

I'd suggest a Low Back Bra Converter (Link merely for show, no idea if this is a good one).

Otherwise, if you've got small, perky breasts, I'd suggest something to hide any nippleage showing through (depending on where you're wearing it - dinner with parents -COVER THEM/drinks with friends -Rock it!), and rock it braless.

I found it! It's called Low Expectations and I have no idea if it actually works but it looks like it might do the trick for a few hours heh. I might have to invest in one next time I have to reach $25 for the free shipping..

Firstly, please do what /u/eriophora suggested! 32A is a very uncommon size, and a fitting bra will help you immensely right away if that is not your true size.

Now that that is out of the way, what kind of back does the dress have? There exist "low back bra extenders," but I have not used them myself so I am not sure how well they actually work. The ones I linked were totally random.

If you have a bra you want to wear with it, you could try one of these doohickies.

How backless are we talking?

You can get one of those adapter things- basically they hook onto the bra back closure, and you wrap it around diagonally. They are like this: http://www.amazon.com/Low-Expectations-Back-Converter-Piece/dp/B00519BDV0
I got one at TJ maxx for like $4. It's good in that it allows you to wear your normal bra.

• If you haven't already, please check your measurements according to the side bar. I can't emphasize this enough and if I sound rude about this I don't mean to, it's just important to finding a properly fitted bra of any type!
  
• How backless are we talking? They make low back converter straps that hook up directly to your bra and depending on how the back of the dress looks that could be an option for you. Typically you wear them so that it hooks directly in the back, loops around your stomach and then hooks to the other side. You can also wear them in such a way that you hook it to the back, bring the wing forward, wrap it around your back, and then hook it up to the other wing (also brought forward). The low-back converter strap method would probably give you the most support, though if it is also a strapless dress I don't recommend using one of these with the "bring it forward first" method because I imagine that it would fall down.
  
• Depending on your size the stick on backless bras may or may not work for you. There are a few different types of these, but keep in mind none of them will give you the same support as an actual bra (at least as far as the information I've gathered so far suggests). There's the silicone chicken cutlet type, the cloth chicken cutlet type, the underwire type, the U-plunge type, the disposable adhesive type, and then there's this type which encapsulates each breast, just to name a few. The problem with many of them (though not all of them) is that they label their sizes as "a-cup," "b-cup," "c-cup", etc. They assume that all a-cups (etc.) hold the same volume. This is completely inaccurate so trying to gauge your actual size is very difficult. Mostly you just have to buy it and try it multiple times until you find your size.
  
• For example: I wear a UK 30G and in a Nubra Original I found the c-cup to be just slightly too large and I ended up going with a b-cup. Though I've also heard from someone else who was about the same size as me that the c-cup and even the d-cup was way too small for them. I think I might be shallow shaped and I don't believe the other person was so breast shape may be an issue when finding one that fits as well.
  
• The Maidenform underwire one that I linked to does list sister sizes, so if you have been sized by the methods on the size bar and if a sister size is available then it could possibly fit. A possible fit issue I could see with these is that the wires could be too wide or too narrow depending. The very last adhesive bra that I listed to is probably the most accurate in terms of sizing, but from what I understand they aren't very low-cut if that is a concern.
  
• Another option you could try if you aren't concerned about support in the least is to use nipple covers and fashion tape to keep the dress stuck down to your skin.
  
  Having gotten through saying all of that, if you have been sized by the methods used here in r/abrathatfits and you end up getting one of these bras, I am currently working on collecting data in a survey so that a more accurate sizing guide could be created. Please fill it out and let us know how it goes for you, but again, only if you've been sized by our methods (and again if my repetitive nature about this is coming off as rude it's not intended to be - I just want to get the most accurate information out there for other people). And if anyone else is reading this, the survey is still going on. I've only had 2 responses to it so far.

The ones I have are these cheap ones but there's a bunch of other options on amazon.
Low back converters might work too