Used sarcasticly - One who when you try to crack a smile from let alone a conversation, it finds you more at odds than as a one legged man in an ass kicking competition. Very uncomfortable and most often resulting in random comments on the weather.
"sooo...its nice to finally meet you...what do you do for a crust"?
"gee thats nice...in what field"?
"So hows about that sky...blue or what" (said with transparent enthusiasm)