You are surrounded by people for a moment of silence when the Giggle Loop begins...

Suddenly out of nowhere this thought comes into your head: the worst thing I could possibly do during a minute's silence is laugh. And as soon as you think that you almost do laugh -- automatic reaction. But you don't, you control yourself, you're fine. Whew.
?
But then you think how terrible it would have been if you laughed out loud in the middle of a minutes silence. And so you nearly do again, only this time it's a bigger laugh. And then you think how awful this bigger laugh would have been. And so you nearly laugh again, only this time it's a very big laugh, it is an enormous laugh. Let this bastard out, and you get whiplash. And suddenly you are in the middle of this completely silent room and your shoulders are going like you are drilling the road. And what do you think of this situation? Oh dear Christ, you think it's funny!
> Coupling - Series 1 - Episode 'Sex, Death & Nudity'