The act in which a tube is shoved into a man's ass and a gerbil let loose inside. The bewildered animal will crawl through shit and eventually tickle the man's A spot, sending him into orgasm. A gerbil may later be extracted by shining a flashlight into the rectum. Note: Always wash your gerbils.
by Anonymous June 13, 2003
Get the Interanal Gerbilationmug.