Scream random swear words in Klingon out loud
Haha, that reminds me. Me and a friend gave a talk at a conference a few years ago, basically a couple of war stories that we thought might amuse the audience. One of mine was about a legal publisher I did some work for, specifically a schema I wrote for them, in which I hid an attribute in Klingon as a protest against them having me write the schema in Swedish (moronic, because most of their devs didn't speak Swedish).
I then had another friend in the audience interrupt me by standing up and loudly swearing in Klingon when I got to the punchline in that story, which was hilarious to me and a few other people and utterly nonsensical to everyone else.

Childish, I know.