The history of images of people having intercourse sometimes reads as a detective story. Evidence was destroyed or disappeared and artists were persecuted or imprisoned.
Some of this explicit material should still be somewhere in ancient libraries where they had a special department for it called Hell.
Around the year 1520 the Italian artist Giulio Pipi, known as Romano, made sixteen very explicit erotic drawings of men and women having sex. These were reproduced as engravings and titled I modi (The Positions). None of them seems to exist anywhere. The engraver, Marcantonio Raimondi did his time in jail, but after his release he worked on another version of this series together with Pietro Aretino, a writer and commentator who also wrote erotic literature.
Their version of the engravings together with sonnets was published in 1527 with the title Sonetti Lussoriosi (Lustful Sonnets). Again, none of these seem to have survived.
We will never know, what the originals looked like. We can only guess, just as this unknown artist did. He created something sexually explicit, yet also gives a hint of timelesness, suggesting mythology in making the men look like gods and giving the environments an atmosphere of a decor.