"Sperm Count" joke

An
85 year old man visits his doctor to get a sperm count.
The geezer's given a jar and told to bring back a sample.
The next day he returns to the doctor with an empty
jar.
"What happened?" says the doctor.
"Well," the old man starts, "I asked
my wife for help. She tried with her right hand, then
her left - nothing. Then she tried with her mouth,
first with her teeth in, then with her teeth out,
still nothing. We even called Evelyn, the lady next
door, but still nothing."
The doctor bursts out, "You asked your neighbor?"
"Yep, No matter what we tried we couldn't get
that damn jar open."