BFF

The most common defenetion is: best friends forever
that is when two friends become supper conected and will be friends forever and alwas together

bff can also can be used as a insult (there the exact opposite btw) theother defenition would be: big fat fuck
i dont know what else to say about this...

look, that girl over there is my BFF we will alwas be togetheer

yo, look that guy over there is such a BFF hes so fat and ugly