A German Blender occurs when you take a girl on a lazy river and lay her inside four or five inner tubes on the water. As she floats down the river, you spin, churning up her insides and causing her to become nauseous. After a few minutes inside the blender, the girl can no longer take it and hurls all over your penis and testicles. She then proceeds to suck it off, making it a sexual experience to say the least.
If you and a girl want to get down, and are at a water park, try the German Blender. It goes as follows.
Cindy: I really want to suck your penis.
Bo: That would be nice, but since we are at a water park, let's try the German Blender!