This is either really bad breath, as in, breath that tastes like a butt, or a physical malformation where one has a tongue protruding from one's anus.
Butt Tongue:

"peee yeeew, you've got some serious butt tongue"
or
"anal with a chick that has butt tongue is hawt!"
by Bigsby333 March 19, 2016
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A slang term for a man's penis. This is normally accompanied by a pair of testicles.
Justin: Man, I think I have an STD on my wang.

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.
by evanempire April 15, 2008
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In the 2001 edition of Ripley's Believe It Or Not, the story of a man named jeffrey summers lost his tongue in a freak accident and had a section of his behind used to create a tongue so that he would retain the ability to speak.

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.
Oh my god, that guy on ripley's believe it or not has a piece of his ass as a tongue!

That guy's butt tongue is hairy... cus it came from his asshole.

Hey look at Colin's hairy butt tongue!
by realeditor March 17, 2009
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This can be shortened to OBT or simply butt tongue. Usually this phrase is meant to insult someone, but can also be used to express that something is uncool.
Ox but tongue is the (fictional) toungue that comes from the butt of an ox. It can also be used with any animal, like cow butt tongue or buffalo butt tongue.
You are such an ox butt tongue!

Man, I can't go to the concert, that sucks major ox butt tongue!
by Inky Ivy February 12, 2009
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A tongue that comes from your butt. An insult to someone. An expression or way of saying something sucks.
Have you checked your butt tongue today? You're such a butt tongue! or Man, that seriously sucks butt tongue!
by Laugh Attack February 12, 2009
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