If anyone's into the history, all the way back to roman times, of UK Brass Rubbing (which I am), the author E.J. Burford has written a couple of great books:
(1). London (The Synfulle Citie) and (2). The Orrible Synne
They make interesting reading, particularly to the modern day practitioner.
In the above engraving, a foreign dignitary in London in the 1100s visits a brothel.
The young nobleman is attended (even in this act) by his Jester, who feigns horror at the proceedings, while slyly peeping through his fingers..
(Cough!)..I never said I was normal...