So many stories, so little time.
I discovered a new friend already knew some old friends of mine. "How well do you know them?" I asked. "We're on farting terms" came the reply.
Riding up in an elevator with my dad when I was a kid. He let an enormous and outrageously smelly fart go. The lift stopped and the doors opened; a man took one step in, a look of horror passed across his face, and he stepped straight out again with a loud "bloody hell". Doors closed and dad and I fell to the floor with uncontrollable fits of the giggles.
I was a teacher for many years. Occasionally I would feel a fart coming on in the classroom. Silently drop it while standing next to a group of kids, then walk smoothly away and listen to them argue amongst themselves over which of them was responsible. A chemistry teacher friend said he always blamed the experiment in progress, but always worried that a kid would write in an exam answer that a particular experiment led to a 'bad smell' when actually it didn't.
I remember also as a 12/13 year old kid, doing an experiment in class where gas was produced and then collected under water in a jar, and realising I could repeat the process in the bath and save the product in a beaker ... and then when I got out of the bath upset my younger sister with a "here, smell this".
Also from teaching days (name changed to protect the 'innocent'). Alone (or so I thought) in the staffroom late one afternoon after school, marking books. Heard a loud fart and knew it wasn't me; I slowly looked round, only one other person there, an old female art teacher (about a year off retirement) called 'Ann Smith'. A few days later, nattering with a couple of close friends and colleagues, including a male member of the art department, I started to tell the story. I got as far as "I slowly looked round" and he said "Ann Smith - she does it all the time in the art room".
My DW always apologised for what she called her "period farts", which were particularly loud and noxious. What I don't understand is why they're just as bad after the menopause.
Riding up on a slow moving chairlift on a dead calm day in a ski resort, me and a friend, with our DWs on the lift behind us, "I've laid an ambush" he announced ... 30 seconds later "Eamonn you bas**rd" from the chair behind/below.