I must've been about 11 I guess. My brother, who is 2 years younger was at a friends place and I was home with mum.
It was a hot day, and mum told me I could play under the sprinkler after the washing on the line had dried and been removed. I needed to pee, but always enjoyed wetting myself under the hose when I could, so I was holding on and waiting till I could play with the water so I could wet my pants on purpose. I put on a pair of really short light blue swimming shorts, and proceeded to set the sprinkler up ready.
I was getting really desperate, but was determined to hold on and wait. I was allowed to pee outside behind some bushes if I needed to, because I had had a habit of holding on too long and having occasionally wet myself a few times as I grew up. But at 11, I hadn't had a real accident for nearly a year, except for my bed wetting. Even that was nearly over, and I was staying dry for weeks at a time with only minor relapses.
Mum called me over, and applied sunscreen to my back and chest. I was starting to feel an uncomfortable urge to pee, and almost lost control when she touched my back with the cold cream. I made an effort not to start potty dancing around though because she would tell me to pee behind the bush, and I was looking forward to going in my shorts.
Eventually she started removing the washing, and by now I was holding myself and crossing my legs, staying well out of her way as I waited impatiently. She startled me a bit when she called out to me to go get something that I'd left on the front lawn.
I potty walked around the house and picked up (my skateboard?) or whatever it was, but suddenly I felt that old familiar feeling. I had waited too long, and was about to lose control no matter what. I froze on the spot, as I felt a sudden warm spot in my pants. I clamped down with my hand, but still felt pee running down my legs. I managed to briefly stop, and walked back up the side to see mum removing the last of the washing. I would be able to turn the hose on shortly.
The next thing, a car pulls up in the driveway on the other side of the house. My brother was being dropped off by his friends mum. I was now trapped on the other side of the house, with my mother in between me and the hose, while she chatted to the other lady.
I just couldn't hold on any longer. I was starting to lose control, and couldn't stop. I had no choice in the matter, but to spread my legs and look down as my bright blue shorts grew dark and pee ran out of them. I was standing in a puddle on the cement.
I stayed hiding for what seemed like ages, then heard the car drive off and mum and Sean go inside. I quickly ran straight for the tap to turn the hose on, and ran straight into mum. She had only opened the door to put the basket inside, and was now removing Sean's shirt so he could play under the hose as well.
She looked up to see her 11 year old son leaving wet footprints behind him while obviously having had a major pants wetting incident, while playing outside where he was allowed to pee.
She asked what happened, and I had to sheepishly admit I was holding on until I could turn the hose on but had misjudged it. We were allowed to pee in our swimsuits so it wasn't a big deal, but super embarrassing at the time.
Sean of course laughed at my misfortune.