Stepsister wants to see her brother's penis

The two young German stepsiblings are alone in the family apartment, chatting. The stepbrother mentions that he hasn't had much luck with women and hasn't had sex in a long time. The blonde teen then suggests that the brother could show her his penis, since their parents aren't home. This is incest, of course, but also perverse and has its appeal. So the man pulls down his pants, which excites the naughty sister, and they have sex.