How to mess your pants/diaper

Me

I tried this technique out a school...
I brought some small pants in my bag and went to the bathroom, making sure to bring them with me. When I got in the toilet cubicle I took off my tights and pants and replaced them with the small ones. I then sat on the toilet in my pants and started pushing. I had eaten beans and cheese on toast the night before, so I was ready to poop a lot. I filled my pants until they bulged and hung between my legs, at which point I took them off, I emptied the mountain of poop into the toilet, wiped my butt and put the pants in the bin provided in each cubicle. I put my other pants and tights back on and left the bathroom to return to class

Details...
At first I pushed on the toilet to get myself started, then I stood up, watching my poop create a large bulge in my pants. It got larger but the poop just kept coming until my pants hung between my legs, swinging as I moved. The poop was warm and half hard, half mushy creating an enjoyable feeling. The sensation was very enjoyable and I will be trying again tomorrow with new pants. (I will be updating the story accordingly)