The Romance of Lust by Anonymous

As yet, I had absolutely no knowledge of the uses of the different
organs of sex. My sisters and I all slept in the same room. They
together in one bed, I alone in another. When no one was present, we
had often mutually examined the different formations of our sexes.

We had discovered that mutual handlings gave a certain amount of
pleasing sensation; and, latterly, my eldest sister had discovered ....