The GFC is that beautiful girl that is a friend of your GF.
The one you are always acting cool with, deepening your voice when talking to, and trying to impress.
You just never feel the need to act this way with Non-GFC.
"Sweetheart, me and my friends will have diner here tonight"
- ok. who..
"hmm Kate, Britney, Mary.."
- eh.. ok.
"and Stacy might also come.."
- ok! fine! (!!!!)
- Man. Not the GFC again. She drives me nuts.