Acronym for 'Flying With Billy Ray'. This is a television show about the popular country singer flying different types of planes and just having a good fucking time.
Can be used as slang for getting high.
Meris: "Hey BM, did you see FWBR last night?"
BM: "Yeah. That Billy Ray is such a crazy mother fucker!"
BM: "Wanna go get watch some FWBR?"
: "Sure. Let me go get my jintttt first."