Punny you should say that

pun
vi (punning; punned) to play on words alike or nearly alike in sound but different in meaning.
n a play on words.
[A late-17c word; origin unknown; Ital puntiglio a fine point, has been conjectured (see punctilio)]

The correct reaction to a pun is a groan. The better (worse?) the pun, the louder the groan. Anyone laughing at a pun is either simple-minded or not very British. The first pun I can recall was made by a fellow pupil, Hudson, in a geography lesson about South America. The teacher made reference to the "hacienda" and was shortly afterwards called out of the room on some business. My fellow pupil Hudson said laconically:
"And hacienda the lesson".
Groans all round. I thought it was hilarious - why else should I remember it all these years? - but learned at that moment that puns are not for laughing at, but for groaning at.

Look at this one (the invention of a fellow blogger):
What South American capital was named after a monkey? Lemur, Peru
Shame on you, D!

I'm not sure if it's really a pun, but I relished an addition that someone made to a poster outside the Albert Hall which announced BACH'S ORGAN WORKS. The punster had scrawled at the bottom of the poster: "So does mine." In all honesty, hard as I tried, I couldn't groan at that. I had to give it a full-on belly laugh.

I was delighted to discover that the pun is not an exclusively British thing. For those of you who know Italian, savour this one. Pierino - who else? - identifies the perpetrators of poo as he walks along a country road. His companion says "How do you know who did what?" Pierino replies, "Gli amici si riconoscono nel bisogno." Another Pierino story, much more scurrilous depends on the double meaning of this interchange:
Mother: "Pierino, Pierino! Le chiavi! Le chiavi!"
Pierino: "Mamma, le ho appena conosciute!"
If you want an explanation, email me privately: this is a respectable blog.