>>3980283
Wetting yourself is far more embarrassing for a shota than anyone else. Being male there's an expectation by society for them to man up and be able to hold it in, and being young they can't just easily laugh off the shame with a simple "accidents happen".
Most boys also strive to be manly and mature, even admitting you need to go would be like revealing a weakness to some of them, so wettng yourself like a baby is one of the ultimate failures to them, especially if it happened in front of others.
it's not that surprising that someone who went through that trauma would develop a fetish out of it.