I was 24 or 25 back then, driving home at night after visiting a friend. Important to note, back then I wasn’t into pooping at all.. it was just another action I had to do every day, and I didn’t give it much thought and didn’t look at others doing it as well.
I had smooth drive for about an hour, then while I was on highway suddenly had urge to poop, out of nowhere. At first I ignored it, planning to take a dump when getting home which was about one hour away, or worst case in a gas station.
After a short time I realized I can’t ignore the urge for long.. it was really really strong, more then I ever had until then.
The highway was still long ahead, at least 15 minutes of driving, with no gas station or even place to stop.
After about five minutes I realized that it’s distracting my mind too much and becoming a risk so decided to just let go right there, while driving. I held the steering wheel tight, focus on the road ahead and stopped fighting the urge to poop.
In the instant I didn’t fight the urge, huge load of soft poop shot out my butt along with very loud fart. I felt it running out, filling my underwear and spreading all over my butt cheeks. It was over fast, maybe 10 seconds, and luckily I didn’t have to pee so the car sit was safe.
I reached home, pants full with poop, and first thing entered the shower, washing the boxer briefs and jeans with lots of water and soap before throwing them into the laundry basket. I didn’t even try to clean myself with toilet paper, just walked into shower dirty with poop and washed it all away, taking out some more poop in the meanwhile.
Didn’t happen to me since, but now that I’m into pooping my pants intentionally I recall this as hot experience and consider making it again, this time on purpose. So far I was able to unload one small turd while driving, still waiting to the time I can shoot really big load into my pants.