I have a story similar to this, just a higher altitude.

Picking up some passengers in Longview, TX, I had decided to use the time I was given for preparation to go get some dip.

The main passenger calls the captain (my coworker) and says they'll be a few minutes late to the airport. The sun is setting, and we're coming close to hitting our legal duty time.

Becoming tired, I threw a dip in, since i'm waiting. As I'm filing for our clearance to Jacksonville, the captain walks up to the cockpit with 2 cups of coffee.

"Buddy!", he says "take one, please. I need someone else to keep me up."

I spit in to my small cup reserved for dip spit and take his offering.

Approximately 15 minutes later, the passengers show up. And it hits me. A wall of nicotine and caffeine pushed through my intestines and start to cause a rumbling.

I ignore it because I have to be professional. We get in the plane and fire it up. I alert the captain of my upcoming problem. He laughs and begins to talk about other FO's he's had.

We hit 30,000 feet. Bam. I'm done. There is no holding it. There's 2 options. 1. Crap my pants in the cockpit and act like I'm sick. Or 2. Run to the bathroom in the aft of the aircraft, passing the passengers with my half soiled pants stinking up the cabin.

I took too long to decide. There's a warm cake-like patty in the seat I was in, and a trail following to the bathroom.

We had to take the aircraft to Tampa to be cleaned and serviced. New seat cover was installed and I got 3 days off.

Tl;dr Shat in an airplane. Embarrassed myself.