Omgg is a short version of the phrase Oh my goodness gracious. Can also be used for those religious types that don't like to use the Lord's name in vein.
oh my god, give up tubby, in my humble opinion. used to mock girls that, while at one point in time were somewhat attractive, have now attended college and gained 15-50 lbs. This is to be used to convince them to just give up on life, being as they wont ever lose that weight.
Suzy Q (the once hot now fat highschool graduate) misses a shot while playing beer pong.
-"OMGGUTIMHO, you suck at this game" -Mike