When I was an English language teacher in Tokyo I would have regular kids classes.
One of these was a new 30 minute class for babies, from about 2 to 4 years old with parent/s in attendance.
One child, lets call her Yuriko, would be crying loudly and grizzling throughout the whole class, from start to finish. Her parents, well dressed, mega-polite and self conscious 20 somethings, would be smiling and laughing (slightly embarrassed by their child 'disrupting' the class).
There was a low table in the classroom on which I placed the class register and the start of every class went something like this:
Me: Tomohiro!?
Tomohiros parents: Here! (smiling at their child, encouraging to raise a hand and vocalise)
Tomohiro: (blank look, maybe grunt)
etc. etc.
The day in question, Yuriko was having her usual meltdown and her mother was sitting politely near me (on her knees, Japanese style) and I was feeling particularly stressed.
We were going through the register with all it's attendant rigmarole... I was standing, then turned and bent over to tick off a name, this meant my backside was now level with Yuriko's mother's face... and I farted, audibly and at length.
I pretended it hadn't happened and plowed on while the poor woman sat there blinking, with a fixed rictus grin.