A funnier, less old-fashioned way of calling someone a "wet blanket". Used when referring to anyone who brings down the fun factor of a given situation. Said individual is as much of an annoyance as an relentlessly itchy scrotum.
"Guys, could you use your 30 cm voices? People are trying to sleep"
"Dude, why do you always have to be such an itchy sac about things? Have some fun already."
The raw, blistered thumb occuring as a result of excessive attempts to get a lighter to work (oftentimes containing a smidgen of fuel to keep your hopes up). Windy days only magnify the chances of developing Flinter's Finger: The smoker's version of Nintendo Thumb.
"Hey buddy - up for a game of Tecmo?"
"Nah, the last thing I need is Nintendo Thumb on top of this Flinter's Finger."