Text speak used in some parts to say something was funny. In a similar way to LOL. It stands for Blimey that is funny, and is only really used by the strange and deluded.
Person one: Look at this image that i have photoshopped, which makes you look like a Gimp.
Person two: BTIF
Person two: BTIF
by A Gimpy Stranger May 15, 2009
by Yrn._.spike July 7, 2018