This is an abbreviation for Codependent Fake Poly Actors.
Someone who is only in a relationships with multiple under false pretenses and Codependent behavior. It is a form of unethical non-monogamy usually for show or status flashing. Many times cheating is involved but kept quite for appearances.
G.C.F stands for Golden Closet Films, they're basically short vlogs, filmed, produced, and edited by the amazing Golden Maknae, Jeon Jungkook of BTS. They basically consist of various shots of BTS in foreign countries, you'll notice some of the members here and there, the G.C.Fs always show the beauty of the scenery and focus on the spectacular views of the landscape.
Your friend: Did you watch Jungkook's latest G.C.F?
You: The GCF in Tokyo? Yes, I did!
Your friend: It was a work of art!