The side fasteners on a babies diaper/pamper is used here as Emergency Flaps. If your emergency flaps are about to blow, have blown or are stretching thin, basically means all hells going to breakloose for a freak out, meltdown, you name it. It's the last straw, you have lost control if they've blown. You still have sanity if they are still intact.
"Dude, if this lady doesn't drive faster than 2MPH my emergency flaps are going to give."
"My emergency flaps blew, I was so pissed I had to leave."
While our lifespan is the number of years we will live, our healthspan is the number of healthy years we will have and our sexspan is is the number of years we will continue to be healthy enough to continue having an active sex life.
A lighthearted reaction upon receiving disappointing news of some sort. Usually something that isn't a particularly a big deal, esp. when it primarily affects someone else - sort of a mild schadenfreude. Sometimes doubled or tripled, and possibly said in a sing-songy voice for added comedic effect to imitate a muted trumpet, which is how the meme originated.