"fgt" could stand for "Finally, Gay Talk" - a term used for initiating an informal conversation hinting at homosexual topics. Don't assume the worst people...
FUCKIN GAME TIME or (FGT) - a term referring to a crew of exclusive alcohlic friends who drink and throw parties every day. Also used as an expression to announce the beginning of a one of these parties.
Your now a member of FGT, lets take some shots.
Vin: Do you know what time it is?
Pat: Its FUCKIN GAME TIME!!