An Oral Sex Maths Lesson: Fellatio plus Cunnilingus equals a 69

Take one man, add one woman, throw some fellatio and cunnilingus into the equation and the answer you get will always add up to 69! If you don't believe our formula, get out your calculator or, if you prefer, check out the following diagrammatic presentation of the problem, which we think you will find also illustrates.

By User:WikipedianProlific [GFDL or CC-BY-SA-3.0], via Wikimedia Commons

By Wikipedian Prolific (Author) [GFDL or CC-BY-SA-3.0], via Wikimedia Commons

By User:WikipedianProlific [GFDL or CC-BY-SA-3.0], via Wikimedia Commons

The Erotic Art of Thomas Rowlandson (1756-1827)

Thomas Rowlandson [Public domain], via Wikimedia Commons

Thomas Rowlandson [Public domain], via Wikimedia Commons

Thomas Rowlandson [Public domain], via Wikimedia Commons

Thomas Rowlandson [Public domain], via Wikimedia Commons

Thomas Rowlandson [Public domain], via Wikimedia Commons

Thomas Rowlandson [Public domain], via Wikimedia Commons

Thomas Rowlandson [Public domain], via Wikimedia Commons

Thomas Rowlandson [Public domain], via Wikimedia Commons

Thomas Rowlandson [Public domain], via Wikimedia Commons

Public Domain

Thomas Rowlandson [Public domain], via Wikimedia Commons

Thomas Rowlandson [Public domain], via Wikimedia Commons

Thomas Rowlandson [Public domain], via Wikimedia Commons

Thomas Rowlandson [Public domain], via Wikimedia Commons

Thomas Rowlandson [Public domain], via Wikimedia Commons

Thomas Rowlandson [Public domain], via Wikimedia Commons

Public Domain

Thomas Rowlandson [Public domain], via Wikimedia Commons

Thomas Rowlandson [Public domain], via Wikimedia Commons

Thomas Rowlandson [Public domain], via Wikimedia Commons

Thomas Rowlandson [Public domain], via Wikimedia Commons

Thomas Rowlandson [Public domain], via Wikimedia Commons