never happened to me....I have a slight feeling a few people at work know but they're decent enough human beings to mind their own business.
If someone ever did say something like "hey do you wear diapers dude?" or something , I'd say, "yes I do unfortunately, but it's better than pissing my pants right?".
It would depend on how rude or, conversely, caringly someone was inquiring. If a close friend asked compassionately, I'd probably just tell the truth. If a co worker or mere acquaintance asked just to satisfy their own curiosity I'd probably just say something like, "yeah I have some pretty bad medical issues with my bladder, I'd appreciate if you kept this to yourself, ya know??"
It's an embarrassing condition and, while effective, diapers are a pretty embarrassing way to manage it. But 5 years in, I've lost most of my "shame" over it. I try pretty hard to keep it private but if some kind of slip up reveals it then whatever so be it. Someone knowing or not knowing is going to have no effect of whether or not I continue to wear them....same with a rude person. Mock me, fine...I'll still be in diapers tomorrow. Point is, crap like that are externalities that can't actually impact me, so I give them the attention they deserve: none.
I'm 38 and work in a very professional white collar career, where HR would not take kindly to someone being harrassed at work over a medical issue. As I have lost most of my shame over this and just want to live my best life, I would really have no problem marching into HR and telling them that a coworker found out about my incontinence and use of adult diaper and that I'm filing a formal complaint.
Out in public, with strangers, I hardly care. I'm sure there have been plenty of times over the last 5 years that I've exposed my diaper reaching up on a store shelf or whatever. Also, changing in public bathroom, the sound of changing a diaper is pretty obvious...Also I don't put wet diapers back in my bag. I carry them to the trash by the sink and toss them, in plain view... I don't care, AT ALL, who sees and never once has anyone ever said something rude.
I honestly think most people (adults anyway) who see my diaper or can tell I'm wearing one probably feel bad for me.