best friends on a boat for x-rays; like bff, but different; can be used to describe a group of friends that are closer than bffs.
bff 1: wow i hate girls who say bff all the time.
bff 2: yeah we should make up another acronym for it just to piss people off.
bff 1: oh i know- best friends on a boat for x-rays.
bff 2: bfoabfxr?