What is Ass Extension?
n. A phrase used by the recipient of a phone call that he or she does not wish to speak with you at the moment. Somewhat akin to "talk to the hand".
"Hello? Oh, it's you again. Listen, my ass's extension is 3459. Let me put you on hold for a moment while I transfer you."
"I'm going to give you my direct ass extension, please call directly next time."