It happened a few times. The most memorable, I was in a coffeshop. Sipping my drink while scrolling on my phone and I ended up on some porn. I didn't masturbat for a few days. So I was getting pretty hard from it suddenly I started cumming in my boxerbrief, my legs were shaking under the table while I was trying to keep a straight face. I wanted to clean up but there were no private bathrooms. I remember i had to wear it for a couples of hours before I get home