Just some limericks I threw together for a thread at a different forum:

There once was a man from Nantucket,
who didn't quite know where he stuck it.
He tried in the front.
But just missed the cunt.
And at last the girl yelled, "Oh, just fuck it."

There once was a blonde name o' Mandy.
Who didn't find men all that handy.
So she asked out a girl,
to give it a twirl.
And decided they tasted like candy.

There once was a priest they called Roy,
who hadn't had much fun or joy.
Till one day at the mass,
the altar boy gave him a pass,
that said, "Meet me in confession with your toy."

i thought it was:

There once was a man from nantucket,
with a dick so long he could suck it,
he said with a grin, as he wiped off his chin,
if my ear were a cunt i could fuck it.

I made up the one in my post. I had probably heard that one your talking about before and it was sitting in my subconscious as I wrote. Though I didn't borrow from it intentionally.