IBF is an acronym for "Imaginary Best Friend". It is used in reference to a celebrity or high profile person who one likes to fantasize about being a friend. It's similar to celebrity crush in the imaginary aspect, but IBF is not a romantic fantasy, it's about friendship.
Reese Witherspoon is my IBF (Imaginary Best Friend), and right at this moment, she is within a five-mile radius of me filming a movie. (From a story called "Pieces of Reese" at NBC4 Washington website.)
Irritable Bitch Face
Guy 1: how did she get offended by that? tell your girlfriend to take a chill pill.
Guy 2: ya i know. she overreacts all the time. she's being a total ibf.
Information between friends
Have to tell you something: but its strictly IBF stuff !!
Initial Bullshit Factor -IBF also known as IBSF.
The Initial Bullshit Factor or IBF is the thing you have to take into consideration whenever someone irreliable, or someone with a history of lying tells you something.
Guy 1- So Joey was telling me about how he had a massive orgy with the ENTIRE cheerleading squad. And immediately I took into consideration his IBF. And so I just told him SFW dude. Your an AWFUL liar. Later I found out he was telling the truth, but how was I suppose to know he lies about EVERYTHING!!