the johnny story...

I asked you to remind me to tell you the johnny story. You didn't. Way to drop the ball.
Luckily, one of us is paying attention.

I work in a perpetual training program. Groups of young people (mostly) are hired at a time and put through a stringent eight week education where they learn the basics of our company's technology. While they are in our program, they are referred to as associates. It's like Airman or Private, except you don't have to be in any kind of shape.
Well. You have to be in some kind of shape. We discriminate against amorphous blobs.

During the time the associates are with us, they have to take many tests to prove their knowledge. (Now that I read it I know the last part of that sentence is really stupid. I guess you would assume, if they were taking tests of some kind, they were attempting to prove their knowledge of something. I hope I did not insult your intelligence.)
One of the most important tests they take is proctored by an outside party.
(See? I think you're smart. I used the word proctored.)
When the associates go to the third party site for the proctoring (snicker) they are not allowed to bring anything into the testing room with them.
About a year ago, I had a large class consisting of approximately 1/2 Irish and 1/2 American and I was addressing them to inform them of the above testing policy. In doing so, I made the following joke.
"You can't go in with anything. You're only allowed to wear a johnny."
This got a much bigger laugh than I had anticipated.
I took full credit for it. I said to myself, "My timing and delivery were impeccable. I am sooo funny."
I found out later that "johnny" is Irish slang for "condom".

I still took full credit for it. A big laugh is a big laugh. I am not proud.