I got this question from a reader in the comments. A squeaking bra sounds hilarious, until it happens to you -- then suddenly it's not so funny anymore. (While we are on a funny note: can you imagine that I keep on typing "squaking" all the time?)
I searched around and found that the squeaking sounds is caused by the underwires rubbing with each other or with the fabric. Often a "flat" (ie two-dimensional) underwire may squeak when trying to bend around a curved torso. If the torso is very curved the underwire has to bend a lot, pulling on the fabric and squeaking in the taut tunnel. A squeaky bra is born.
In case any of you happen to buy a bra that squeaks, probably your safest bet is to return it. Another thing -- I've read that putting your bra in the dryer might cause it to squeak, so air drying is best!
But what if you're stuck with a squeaky bra that is too good to throw away? Washing the squeaky bra a couple of times helps in some cases. Unfortunately it didn't help our reader, even though she tried using fabric softener too. I have heard that a bit of talcum / cornstarch / soap might help lubricate the spot and end the squeaking. Unfortunately I didn't find another solution, so I'm turning to you gals: does anyone know of an effective way to get rid of squeaky underwires? Do you think bending them around the torso would do the trick?