Inappropriate Laughter

I have decided that there is a medical condition for my laughing at very inappropriate times.  Have I found or even looked for a name for this condition?  No, but that's beside the point.  I'm sure it's out there. 
I believe it started when I was in the seventh grade.  I was in church (with my father speaking as a guest) when an old man behind me started burping these outrageous burps.  I couldn't take it, I lost it - uncontrollable laughter.  On second thought maybe my condition started as a child when I shared a bedroom with my sister.  She could always contain her laughter but it would be me that would get us into trouble with my big mouth:)  Anyway, back to the church scene....I received my last spanking from my father that night.  I was in seventh grade but couldn't contain my laughter in the church house!
My problem continued into college when I again was in a church service (maybe that's the problem - church services) when I looked across the sanctuary to see one of the lead deacons dressed by his wife in baby blues, pinks, and maroons which by the way, she was also the interior decorator for the church (I would recognize that color palate anywhere).  Again, I lost it.  Why can't I control my laughter like other people?  Why do I find rather normal things hysterically funny?
Well since then I've gone on to laugh at funerals, laugh uncontrollably at the edge of the aisle of my wedding, laughed when a friend shared with me her husband had cheated on her, I laugh when I am extremely mad at my husband and nothing comes out but laughter - I can't make any solid arguing points because I'm too busy laughing.  My list could go on and on.  I believe the stress of these situations send me over the edge.  I don't know.

Well, last night is my latest addition: Dos' violin recital.  Other parents lovingly watch or film as their children try their best to share what they've learned this year. Me?  I get tickled at the mannerisms of my little man and lose it.  I mean, have to walk out the back of the church (Again, with the church.  Maybe I am on to something) can not control myself.  Everyone was following the instructor as they should and he just stayed in his spot concentrating so hard on what he was supposed to do. Oh how I love that boy.
Any pointers on how to keep the laughter in check?