Essentially the effect given to the inside of the toilet bowl right after getting the beer-shits, thus resembling the outside facade of certain british pre 1970's council homes, where small stone pieces are spread over the outside wall giving a textured effect.
Tarquin: 'I wouldnt go into the bog for a good half an hour mate'
A game in which Geoff must run quickly and gather small, smooth stones. Having collected several hundred he then thrusts them up the arse of his long-suffering partner... the Tonibitch. Toni then bends over, and having eaten a Madras the night before, lets rip the foul delight of shit-stained stones onto Geoff's erect cock
Geoff: "Bend over you rotten cunt, I'm pebbledashing"
Toni: "Must we? I'm really tired of all this shit, can't we just make normal love"
Geoff: "Jesus... you fucking freak!"
Toni: <sigh>