"The wrinkles (Adult Joke)" joke

There's this middle aged lady who goes to her cosmetic surgeon
to see what her options are concerning her rapidly sagging face.
"We can give you an old fashioned face-lift," he says, "or we
can use a new high-tech procedure called' the knob.'"
"What's' the knob', doctor?", she asks.
"It is a procedure where we install a knob under your hair on
the back of your head. We then connect it to the facial
muscles which sag, and whenever you start to notice any new
wrinkles and sagging, just tighten the knob a few turns and your skin will be nice and tight again."
"Oh, YES, doctor! That is what I would like to have", she says
excitedly.
The operation is a complete success and she looks 15 years younger. As time passes, whenever she notices any new sagging, she simply tightens the knob and VOILA! Her face is again beautiful. One day about 8 years later she wakes up one morning and sees two very large bags under her eyes. Alarmed, she calls her doctor and reports the bags.
"Come down to my office right away and let me check it out!" the doctor says. After examining her, he says, "You've been tightening the knob WAY too much!! Those bags under your eyes are your breasts"
The lady says, "Well! I guess that explains the goatee!