A 1959 Robert Bonfils illustration lost for fifty years, this inside cover for Fling Festival Magazine Volume one Number one 1959 (Collectors Annual issue). Since early smut like this is fugitive literature of a sort, I guess we are lucky to have it at all.
Robert Bonfils is generally considered the finest illustrator who worked on vintage sleaze paperbacks, but that wasn't his whole career. He did lunch boxes! He did record covers. He did them all well with a very unusual, unique style usually far exceeding the esthetic quality he was providing a package for.
Bonfils was usually on the outside of the book, but this illustration was the inside front cover (with an unusual bleed over to the title page of the novelette in black and white.) As you can see, the cover here has slipped a bit, but then I don't think too many of these issues are still around. A striking work by a striking vintage sleaze artist, and from a place not too many folks would have seen it.
Bonfils site is HERE and it is recommended!