1) "Cunning linguist" simply sounds astonishingly similar to cunnilingus.
2) Whoever discovered the phrase "cunning linguist" certainly was one.
3) A "cunning linguist" would have a dexterous mouth, aiding him or her in the act of cunnilingus.
This word play is a triple whammy!
(2) Slang for pussy eater as it sounds like "cunnilingus".
BTW, my old softball team, Cypress, California, was named the cunning linguists, and we "licked" most of our competition.
Julian McMahon played the part of a cunning linguist on the TV show "Nip/Tuck".