lunning cinguist 

One with great wit and ability when it comes to use of the tongue. (Also known as oral sex). It is derived from "cunning linguist" with the first letters switched around. Much like "bucking fitch" and "fothe mucker". It was first used on Facebook when someone mistook "cunning linguist" for "lunning cinguist". Its meaning is the reverse of cunning linguist. The person in question has sloppy techniques with their tongue, hence the miss speaking of words as well as implying lack of skill with oral sex. Two lunning cinguist performing 69 is sometimes called lunning cinguists.

David: "Ya mother is a cunning linguist!"
Rachael: "Don't you mean "lunning cinguist"

lunning cinguist by Tony Young September 6, 2011