prison life bound to be dull, but due to years of [fisting] the convict managed to bring 3 kilos of [smack] and a [boombox] in his prison wallet
"the anal cavity of an inmate, so named for its ability to smuggle valuables into a prision or stash them for safe keeping
"prison life bound to be dull, but due to years of [fisting] the convict managed to bring 3 kilos of [smack] and a [boombox] in his prison wallet" What is the definition of "prison wallet"?