Liquor liar

A person that is quick to say they don’t drink alcohol, but will drink willing when it is available.

Drinker: I heard about this new Gin that is supposed to be really smooth; I’m going to try it out this weekend.
Liquor liar: It is probably not good, plus I don’t drink liquor.
Drinker: You drink with me all the time; you are such a liquor liar.