Hi Tramned! Yeah I do this too. I think it's a nervous thing but it really winds people up.
Sometimes during a row with my husband I'll start giggling uncontrollably. I also laughed right the way through my wedding vows! It was torturous because everyone was looking but I just couldn't stop. I felt my face get hotter and hotter and could feel all those eyes on me...*shivers*
I had to run out of the room when I was given the news of a relatives death. Everyone thought I was overcome with grief but really I had to escape before they witnessed the hysterical laughter I could feel bubbling up.
The latest episode was during a meeting with my son's psychologist and his preschool teacher. They were talking to me about his behaviour in the nursery and about the support plans they wanted to put in place to help him prepare for school. It was supposed to be a serious discussion but I just kept picturing his cheeky little face and was picturing him in my mind doing all the things they were describing. The psychologist then had to witness what she probably thought was a terrible (or drunk) mother, wobbling like a jelly with her face getting pinker and pinker, giggling and snorting while she listened to the difficulties her child may face.
I think it may be because they sounded so solemn and so serious. Not good!
God created the world in 7 days.... a foolish brag I feel!