A bloke sees a sign in front of a house in Petersham: "Talking Dog for Sale."

He rings the bell and the owner tells him the dog is in the back garden.
The bloke goes into the backyard and sees a black mutt just sitting there.

"You talk?" he asks.

"Sure do," the dog replies.

"So, what's your story?" The dog looks up and says, "Well, I discovered my gift of talking pretty young and I wanted to help the government, so I
told ASIO about my gift, and in no time they had me jetting from country to country, sitting in rooms with spies and world leaders, because no one
figured a dog would be eavesdropping. I was one of their most valuable
spies eight years running."

"The jetting around really tired me out, and I knew I wasn't getting any
younger and I wanted to settle down. So I signed up for a job at the
airport to do some undercover security work, mostly wandering near
suspicious characters and listening in."

"I uncovered some incredible dealings there and was awarded loads of
medals. Had a wife, a few puppies, and now I'm just retired."

The geezer is amazed? He goes back in and asks the owner what he wants for the dog. The owner says, "Ten bucks"

The bloke says, 'This dog is amazing. Why on earth are you selling him so cheap?"

"Cause he's a f*ckin' liar. He's never done any of that stuff."