A phrase meaning something along the lines of 'oh come on, you must be joking' but made all the funnier because it is usually exchanged between white kids, and obviously refers to weed.
"Nigga, you wearin' Skin Bracer? Aint no bitches gonna be fuckin wit you."
"Nigga please, you know I aint splashin' no boosit on me, Im a through nigga."