I'm of the school of thought that you can talk about what you want, but realize that if you're not very VERY careful, you're going to end up in a Jay Leno monologue.
Flying back from where ever in hell I was last week (don't laugh), a flight attendant calls the cockpit and the captain says "Wazaaaaaaaa! Hello? Hello?". I look down and he's broadcasting over Gander Center. I deselect him from COM1 gave him the "cease fire" signal and kept doing what I was doing.
See, I didn't laugh at him because there are those that have and those that will again!
My freshman year at Southernjets, we jumped onto a 727 and I was testing the oxygen mask microphone. I tested the oxygen and then the mic by saying "POOOOSH Luke... I am your far tha!" over the PA.
Little did I realize that it was a "through flight" and there were about 30 passengers onboard. Most laughed, but a little old lady looked like she was about to have a myocardial infarction.