If you add a fic to the stories section that has only incidental popping at best in particular chapters, please mention which chapter here. Not a requirement, but the gesture is appreciated.

Equinox (This story has a lot of explicit sections.)
Chapter 4 - Applejack has fun with a balloon.
Chapter 5 - Spike and Twilight have fun with a beachball.
Chapter 8 - Celestia has some fun with a balloon.
Chapter 9 - Twilight and Rainbow Dash + Twilight and Spike.
Chapter 10 - ?????
Chapter 11 - Spike with Sweetie Belle. ()
Chapter 14 - Fearful play between Twilight, Celestia, and Spike.
Chapter 15 - Fearful Spike (from Rescue from Midnight Castle) plays with some other ponies.
Chapter 17 - Shining Armor fearful play.
Chapter 18 - Popping with darts. Ponies and squirrels.

Fallout: Equestria - New Pegas:
Chapter 3 Dance Hall Daze - Contains automated overinflation in close proximety to the lead OC protagonist.
Chapter 14 The Good the Bad and the Derpy - A lot of exploding balloon-suits. The suits, however, are filled with hydrogen instead of helium...
Chapter 15 Bubble Trouble - Popping balloon-like bubbles underwater. There's a pony trapped inside the bubble.

The Sweetie Chronicles: Fragments:
Chapter 6 Part 4 The Best night Ever - Fade - A brief co-op during a song involving a Pokey Pinkie team-up. + Blueblood pulls a prank on Sweetie Belle, startling her.

Equestria Girls - Not a fanfic, but I figured I'd mention that there's a little bit in the movie.

I need to check out a lot of these stories like Equinox. Popping Pupil is more or less a safe story since there will be some popping and some funny stuff. I want to make it safe at least.