Acronym for "Sing" "Eat" & "Go" in that order.
Mainly done at birthday parties, The act of one going to a party for a short moment and only singing happy birthday and eating, then soon leaving casually.
Person 1 : Ugh i got to go to this party tomorrow
Person 2 : I thought we were gonna hangout
Person 1 : Ill be back soon I'm just gonna S.E.G.
Shit Eatin' Grin. A smile on the lips paired with an oblivious look in the eye. An SEG can be alcohol-induced, pure ignorance, or just not giving a crap what anyone else thinks.
He wasn't wearing anything but that S.E.G.!