All day spent on the couch generally not giving a f*ck about the world or interacting with the human race. Wrapped in a blanket, it's the ultimate chill day. Waisting your entire day watching TV, playing video games, watching movies, often times in your pajamas and not showered for the entire day. B.i.B usually occurres following a long work week, a night of heavy partying, or when your home sick.
Ex 1) You're hungover? Are we gonna see you later or are you B.i.B (Blanket in the Butt)?

Ex 2) I had a f*cked week at work, I'm B.i.B all weekend...

Ex 3) I've got the cold from hell, I'm B.i.B with some hot & sour soup and Theraflu.
by T. Dub January 12, 2013
Get the B.i.B (Blanket in the Butt) mug.