It's hard to believe, but in the 1870s and 1880s there was a fashion for massively padding out the bottom of a dress at the back. The cushioning needed to be supported by a frame of wire or bent willow. The purpose was to emphasize the woman's derriere. This structure was called
a bustle for a dress. And that's the only time in European history that it has been safe for a man to answer "yes" to the question "Does my bum look big in this?".