I don't wear the same bra every day, but I also don't wash bras after every wear. I've found that if I wash them every day, they fall apart so much more quickly.

All you weirdos who basically "never" wash your bras, take one of those that you've been wearing for "months" and mash it into your nose and take a deep breath. Trust me, they smell. Wash your bras more often, freaks!