my grandmother used to let out a 5 minute 5 octave fart in front of my cousin and me, and then calmly go 'sorry, that one just slipped out'..
and we couldn't stop laughing. of course we were 12 years old at the time.
the thing is, I think I would still be laughing 20 years later
I guess when you have been farting for 85 years, you don't get so embarassed anymore..