This is not worksafe (it has two or three nude photos), but this old-fashioned Japanese sex manual is one of the funniest things I have seen in a long time. The captions below the photos are great. About the diagram below, the commentator writes: the important things are, 1) it’s a 2 dimensional CUT-OUT of a woman, with what appears to be rubber boobies glued to it, and 2) ARROWS. The only thing they left out was the “honk-honk” clown-horn noise. I love how the arrows make no sense, yet make it seem so scientific.
BTW, one of my prize possessions is a 60’s sex manual, Sexercises: Isometric and Isotonic. Maybe I’ll scan some photos from this equally hilarious book. For those who are wondering, the book is available on amazon for under a dollar.