The following is a transcript of things overheard in a restroom earlier today.
ME: [Sidling up to a urinal and liberating the Little Fireman] *tinkle* *tinkle* whiiiiiiiiiiiiiiiiiiiiiiiiiiizzzzzzzzzzzzzzzzzz...
SOUND FROM ONE OF THE STALLS (SFOOTS): *fssssst* *poot* *Brrraaaap*
SFOOTS: *brrrap* *brrrrrrap* BWWWWWWWWWWWWWRRAAAAAAAAAAAAAAAA-AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA-AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA-
[Approximately 15 seconds later:]
ME: [Eyeballs popping out of head from suppressing laughter] *pfft* *cough* *pfft*
At this point I was done with my business. I zipped up and headed to the sink to wash my hands. While doing so, I noticed that I had the most bizarre looking grin on my face; a look of combined mirth and pain - pain from stifling a laugh that had a force of approximately 300psi and growing.
I maintained this odd expression as I left the restroom. A fellow member of the Filled Bladder-Based Community entered the loo as I was exiting. He gave me a strange look. It was only later that I realized with some amusement that he had no idea why I was wearing such a shit-eating grin on my face, having arrived in the restroom after the gastric aria had concluded.
Then I realized with some horror that he'd probably attribute the smell in there to me - the weirdo who flashes an odd smile at other guys entering restrooms.