When I get the giggles at the most inappropriate times. Like say during worship at Ladies' Bible Study.
I couldn't control myself and Sarah wasn't helping. Every time I looked at her I was sent into another round of laughter. You know the kind, you try to be quiet, but it's impossible. Your shoulders shake uncontrollably and you cry.
It took a while for me to regain control, but I felt really bad about it after.
(note to self: next time I mess up on a song, don't look at Sarah)