German Cup Match Invaded By Surprise Anal Sex Tours

The hanging of flags and banners by soccer team supporters' groups is a tradition as old as the game itself. But what the hell is this, spotted during last night's DFB Cup match between Eintracht Frankfurt and Borussia Dortmund? Is there really a a Frankfurter booster crew called Anal Sex Tours?

Maybe it's a guerrilla ad campaign. After all, the flag next to it seems to be mentioning a beer. Maybe Anal Sex Tours is a beer, too? Can anyone explain this?

h/t to Brian