Premise: "Oh! Mr Porter" is an old British music hall song about a girl "going too far". It was famously part of the repertoires of the artistes Norah Blaney and Marie Lloyd. It was written in 1892 by George Le Brunn and his brother Thomas, and taken on an extended provincial tour that same year by Marie Lloyd. The lyrics include this chorus:
Hypothesis: 1892 was a tumultuous time and thats why the song caught on