The result of having a section of your ass removed to serve as a replacement for your tongue which has been destroyed due to unwarrented participation in certain intriguing activities.
That guy's butt tongue is hairy... cus it came from his asshole.
Hey look at Colin's hairy butt tongue!
Tyler: Have a canker sore on your butt tongue, huh? That sucks.
Justin: Butt tongue?
Tyler: Didn't you listen in anatomy class? Your wang is the tongue of your butt. Thus butt tongue.