How about when you laugh out loud during a meeting at the site of a female coworker spinning in her office chair....and try to explain to the boss what's so funny about a spinner.
How about when you're brother's fiance mentions over a family dinner how she really needs to get a facial and you have to leave the table before you start laughing.
Or when a very good friend's fiance's mother tell you how limber she used to be in gymnastics and you blurt out what a lucky guy he is (at their wedding rehearsal no less).