Acronym for "Best Friend to the Grave". It is a cooler sounding acronym for BFF of BFFL, since those sound kinda gay. Not as extreme as a BFTIKU, "best friend till i kill u". i made it up summer of '08 when i was bored and decided me and my freind would make up acronyms. so next time you want to impress your friends, tell them they are your BF2TGs. It can be used to describe anyone who u like.
Dude A__: You are my BFF dude!!!
Dude B__: That sounds lame dude. BFF
Dude A__: Woah sorry dude i dont know what hit me, that was totally uncalled for, u know you are my BF2TG.
Dude B__: Ok i was scared for a moment, but now that you used the phrase, you are totally awesome.