The "Bed Series" was a set of intimate portraits of lesbian sex workers made by Henri de Toulouse-Lautrec in the 1890s behind the scenes at a Parisian brothel. More here:

The Public Domain Review

Henri de Toulouse-Lautrec’s Bed Series: An Intimate Look Behind the Scenes at a Paris Brothel (1890s)

A series of depictions of prostitutes, likely lesbian couples, drawn and painted in a Paris brothel during the Belle Époque.