In German pedestrian precincts you'll frequently view the sign "backshop". Ingenuous strollers might come to the conclusion that this was simply a bread shop or bakery which an advertising poser named with a pseudoanglizism to appear cosmopolitan, educated or fashionable.
Far from it! In fact it's a veiled invitation to sodomize (in other words fucking the backside) male or female hookers which are for sale there and the actual main source of revenue of the place. In some cases (mainly if the costumer is attractive enough) there is of course the possibility of a free shag as well.
Among gays a backshop is commonly referred as "darkroom" with the light (still) on.
Detlef: "Hey there is a backshop. I got some free time on my hands. why not go in there and get some "proteines"?"
Some pedestrian: "You filthy cum guzzling fag! Hope you'll catch a disease in there and perish!"