character likes wearing padding!! it's comfy! but... they've never actually used it before. either it's never crossed their mind, or they've been too shy to actually allow themself to do that. but then while they're padded, they realise they're in a situation where they can't reach the toilet, and have to decide between trying to hold it (despite how difficult it's getting, how insistently they can feel their bladder throbbing) or just letting go
they have to wear diapers through the night just in case they wet the bed, and it's fine, they don't have any issues with that. but then they have a friend staying over, and there isn't anywhere else for them to sleep- and they can't just let their friend sleep on the floor that'd be rude, and their friend won't let them sleep on the floor either, so they have to awkwardly explain the situation (bonus things to consider: how does their friend react? are they supportive, do they not care? and, do they end up wetting themself during the night? do they have to sneak out of bed to get changed? does their friend wake up and offer to help?)
it's their first time wearing a diaper, and they really like it! but they get too caught up in how comfy they are in it that they forget to go to the toilet until it's too late, and they wet themself in it when they maybe weren't prepared to go that far yet
going shopping for diapers/pullups with cute patterns! maybe they bring a friend with them who's also interested and they have a fun time together looking through everything!
also for the sake of interpreting the word 'padding' in a non diaper way. thinking about someone getting all their warm thick clothes on because its so cold outside so they can go out and maybe have fun in the snow if there is any, only to realise after a bit that they really need to go. but it's fine! the clothes they're wearing are really thick, so surely that'll be enough to absorb it even if they end up having a tiny accident. unfortunately, they Do Not have a tiny accident. they needed to go far more than they realised and by the time they realise there's going to be an extremely obvious wet patch on their clothes it's far too late for them to stop
