bfbtu is wen ur bffl dose something with out telling u

e.g my bffl new i like this guy and one day i said hi babe like we do and he tolded me he was thinking we shud just be mates and i said y he said he had a gf and wouldnt tell me who and it was my bffl and she didnt tell me my own niece did and she now nt my bffl