I thought this was an interesting question, so I decided to do a GBT (Google blush test).
I ran three searches each, on the terms bustier and corset.
- The first search was on Google Images.
- The second search was on Google Images, with Safe Search off.
- The third search was on Google Shopping.
The results were rather interesting. When I checked Google Images, the bustier pictures seemed a little bit racier, although the difference was only slight.
However, when I switched the search from Images to Shopping, the results were reversed. The sites from the corset search were packed with racy and tacky costumes (Wonder Woman, anyone?), while the bustier results revealed much more understated undergarments.
Hence, bustier might indeed be the "sexier" word, but that may not be the end of the story, particularly if an e-commerce site is trying to determine how to get keyword hits.