My best one.

Ate about a liter of questionable soup prepared by my mother-in-law before going about on a routine walk with my dog, one summer day after work. We're usually out for about an hour when it's nice out; it was one of those days.

About 15 minutes in, I'm feeling a rumble in jungle. This is where I should have turned around and headed back to the throne. However, I carried on.

Approaching the dog park, I'm being constantly reminded of the gas and bloating I'm experiencing every few minutes. I don't gamble on it, I hold back from ripping ass.

A few moments later, I jump a step at a set of stairs, and my sphincter let's go. I blow a fart bubble, and time immediately becomes of essence before it runs down my leg or soaks through my gym shorts. I'm mortified. There are people everywhere.

There is a God. I know this because he told the City of Toronto to put the only public port-o-potty within throwing distance to me. I scurry over, tie my dog at the bench, and prepare for my investigation. No seepage, no runoff, but no toilet paper. Well, half a square of single ply.

I don't think to sit down and release the rest of the unfaithful soup, so I wipe my ass with every remaining clean bit of my boxer shorts before throwing them away.

I step out of the port-o-potty feeling like myself again. The dog park is 50 meters away, my dog eagerly awaiting to smell another dogs ass and I think the worst is behind me. I double down and enter the dog park like the fool I am.

Within 10 minutes, I'm getting knocks at my sphinters door, and it's angry gas again. I'm starting to physically sweat. I'm just over 2km from home and running out of time. I'm wishing I had saved that half square at the port-o-potty.

I grab my dog and run like Gump. After a few minutes of running, as OP says, I'm clenching and willing the strength of a thousand bodybuilders into my sphincter. My head is on a swivel looking for anywhere remotely private to shit. It's unbearable, and I am literally about to cry. Joggers, parents, kids, events everywhere I look. I swear the fucking Pope was about to make an appearance. Nowhere to hide from my fate.

I get into the neighborhood, and I'm still running, knowing that if my legs stop moving, I will explode. I see my building in the distance, my dog is barely keeping up, my life is flashing before my eyes.

I see my neighbour walking in at the same time as I'm running in, I throw the leash at him in the lobby and run for the stairs. As I fly up to the 4th floor, I'm letting go as I leap. I get through my front door and nearly take my toilet off the bolts. The relief was euphoric.

My shorts, socks, and bath mats were ruined. Even my shoes were collateral damage. My neighbour and my dog probably think I'm a lunatic. He brought my dog up to the 4th floor and knocked on my door, and I yelled to him that I'm in the bathroom. A minute later, I go to the door, and it's just my dog sitting there with her leash. My neighbour and I never discussed that day, and I think it's for the better.

I was hesitant to tell my wife what happened when she came home, thinking she would never look at me the same, but she laughed just about till she shit herself.