Bit of my own. Well, Stephen Fry really but I repeated it :-)

I was taking a stroll through the meadows when I stopped and bent down to inspect a flower

"What are you doing?" asked my friend

"Picking a buttercup" I replied

"Who on earth would leave a buttock lying in a meadow..?"

Now back to the main show...

A bloke is trying to chat up a lovely young woman he's just met in a bar.

"Have you ever seen a penis?" he asked her, ever so subtly.

"A penis? What word is that?? Never heard of it!"

Well come back to my place and I'll show you mine!"

So they go back to his place and he, er, whips out his willy.    "So what do you think?"

"Ah, so that's a penis then!" she replied. "It's just like a dick, but a lot smaller!"