The act of fast paced and rapid anal pleasure, then a sudden removal of the penis (or other tool) from the anus. The outcomes are usually rather spectacular, as shit literally hits the fan (and everything else in its path).
Usually best enjoyed with 2 or more people.
Frank: Hey man, I heard your wife let you try anal with her the other night. How'd it go?
Dave: I pulled out too fast, and shit went flying everywhere, last time I try that..
Frank: aahh, the Plunger Effect