GET D! RTY! Next time you're signing with your friends, drop the ASL textbook formality and start flashing the signs they don't teach in any classroom, including:- cool slang- funny insults- explicit sex terms- raw swear wordsDirty Sign Language teaches casual everyday words and expressions like:- Peace out! - Asshole. - Bit me! - Dumbfuck! - Boner- I'm hung like a horse.