"Face-lift" joke

A
man decides to have a face-lift for his birthday.
He spends $5,000 and feels really good about the
results. On his way home, he stops at a newsstand
and buys a paper.
Before leaving, he says to the sales clerk, "I
hope you don't mind me asking, but how old do you
think I am?" "About 35," was the
reply. "I'm actually 47," the man says,
feeling really happy. After that, he goes into
McDonalds for lunch and asks the clerk the same
question. The reply is, "Oh, you look about
29". "I am actually 47."
Later, while standing at a bus stop, he asks an
old woman the same question. She replies, "I
am 85 years old, and my eyesight is going. But
when I was young, there was a sure way of telling
a man's age. If I put my hand down your pants and
play with your balls for 10 minutes, I will be
able to tell you your exact age."
As there was no one around, the man thinks, What
the hell and lets her slip her hand down his pants.
Ten minutes later, the old lady says, "Okay,
it's done. You are 47." Stunned, the man says, "That
was brilliant. How did you do that?" The old
lady replies, "I was behind you at McDonalds."