The thought of using your diaper crossed your mind. Though it would be gross to go to the bathroom in your pants it would score you some private time with Heather given that she'd likely end up changing you. Just thinking about her cleaning you up brought a big smile to your face. Purposely having an accident was well worth the embarrassment if it meant Heather touching your privates, despite them being toddler-sized. Also it was only a matter of time before you ended up doing your business in your diapers anyway so might as well do it on your own terms. Plus it should be easy given the huge lunch he had before he went shopping.
Toddling over to a somewhat secluded corner you prepared to use your diaper in as discreet a fashion as possible. You attempted to pee and were surprised that after only ten seconds of trying you were able to coax out a steady stream. As you quietly stood there wetting your padding a odd sense of relief washed over you from your bladder emptying. That is until a pressure in your rear made itself known. Before you had time to react the head of something solid was coming out of your butt. Following some sort of instinct you bent your knees in a half squat as you began to push, pooping out a huge turd at the same time you finished peeing. The size of the log quickly filled the empty space in the back of your diaper, causing the back to bulge out significantly. When it was all over you stood back up perplexed at how natural the whole thing felt. While it was definitely gross to go to bathroom in your underwear, it wasn't quite as bad as you originally thought it would be. You figured the regression to such a young age made you more inclined to such infantile actions. Nevertheless you still wanted out of the dirty diaper as soon as possible. The only thing now was to figure out how to go about getting a change.
Looking over at Heather you saw she was entertaining a pair of toddlers with some toys. Considering your limited options you could either go over to her and tell her what you did, simply play next to her until she eventually notices the smell, or do the baby thing and cry until she changes you.
After much internal deliberation you decide to...