This only happened to me once or twice, and always after I'd been caught indulging in some of my early experimenting.
The other day in another thread I was talking about how--when I was about 5-6--I'd hide in the basement and pee in my pants and hide them in a plastic bag, eventually my mother found them and I had some explaining to do; I made the mistake of telling a friend who blabbed it to another kid down the street who showed up a few days later standing in front of my house yelling "I HEAR YOU STILL WEAR DIAPERS!" Well, my mother wasn't angry at me over this but told my father--a former military guy with a bad temper--and he got angry and started threatening me, it was "YOU BETTER STOP THIS or YOU'LL BE BACK IN DIAPERS!" And I do remember liking the idea of the diapers, but knowing with him that each diaper change would include him spanking my ass first. So, no more experimenting for a long time.
Several years later when I was about 12, I was outside playing basketball and had to pee and some leaked into my underwear/pants. It was a cold day and the warm pee felt wonderful so I then intentionally peed in them some more. When I returned home there was a big wet spot in the front and my father saw this. This time he laughed and asked "Have an accident?" I told him I had and that was the end of that. Until a few days later when I mistakenly thought "Oh he doesn't care about this" and intentionally wet my pants again. This time he lost his temper and started yelling about how "I KNOW YOU'RE 12 YEARS OLD but you're NOT TOO BIG TO GO BACK INTO DIAPERS!!!" Again, I loved the idea of the diapers but was scared of him so, no more of that. (Though this was about the time I seriously started having fun with this, doing the old "towels and trash bags" thing on nights when my parents weren't home and making sure that they never found the evidence, but that's another story).
Then, about 4-5 years later there were a few other incidents that I remember. By then, I was seriously into wearing my makeshift "diapers" whenever possible, wetting my pants, hiding the evidence in the closet, smelling all of my peed-in clothes while getting myself off with spectacular orgasms. After seeing a friend's little sister going around in training pants I wanted a pair, there was no internet back then and I had no idea if it was possible to buy any so I made myself a pair by taking three pairs of "tighty whitey" jockey shorts, putting one inside of the other, and sewing them together. I'd wear and wet those then let them dry in the closet, do it again, loving the way they felt and smelled. One day I came home and my mother had found these and was holding them in her hand. I was now a teenager, I didn't get threatened with being put back in diapers--rather, this time it was "Do you need to go to THE DOCTOR?" I got rather angry over this, told her "No, I don't, I'm fine." She apologized for invading my privacy. Fortunately this time she DID NOT tell my father! It never was mentioned again.
About this same time, I had a male friend who had a little sister who probably was about 12-13 at the time and kind of cute. Over the course of a month or two, she'd apparently had several incidents of wetting her pants. Typically they'd be driving somewhere, prior to leaving she'd be told "If you have to use the bathroom use it NOW" and she wouldn't, then later in the car she'd pee in her pants. (My friend, her brother, had told me about this and about how his parents had been talking about "If she doesn't stop this, we'll need to get a plastic seat cover for the back seat!")
There were also a few times when she had to go, and she'd see something funny and start laughing so hard that she'd wet herself. I remember being over there once when this happened, given my own love of all of this I already had a raging hard-on from seeing her do this and wishing that I could find a way to enjoy her wet panties. Then their father came in and started yelling at her, "I'VE ABOUT HAD ENOUGH OF THIS AND IF YOU DO IT ONE MORE TIME, YOU'RE GOING TO TO BE BACK WEARING DIAPERS AGAIN!" By now she was crying, still sitting there in her puddle of pee and crying like a little kid...I was secretly wishing that she'd be taken back to her room and come back out later in a t-shirt and diapers. Didn't happen, but over the next few months I probably jerked off 500 times thinking about this. On several future visits I found pairs of her panties, on the floor, in the basket...there was always a big yellow pee stain in the crotch, either she leaked a lot or still wet them to some degree. They smelled wonderful and I "enjoyed" them accordingly.