An elderly couple in a senior's home

An elderly couple in a senior's home used to visit the recreation room
everyday. While
there, the old lady would sit quite contently holding the old guys's
penis. One day she goes
down to the rec. room and is mortified to find her man with another
women holding his
penis. "What's she got that I don't have" she says. He looks up with a
large smile on his
face and replies "Parkinson's"