I was sitting in class, and dropped my pen under the desk I bent to get it and RRRIIPP!! my pants split from zipper to waistband!
Realising my pink and white checked frilly panties were exposed, I began to straighten up. WHAM! I smacked my head on the desk! I was a little shaken but okay, but my teacher insisted I go see the nurse. When I refused she became convinced I had brain damage or something, and told two other girls to help me. By now the whole class was watching as I was stood up, my fat ass bulging out of my ripped pants (the girls had an arm each, so I had no way of trying to hide it) and walked slowly out of class, then to get to the nurse I had to walk outside the windows of about ten packed classes, and a full sports field, showing my ass to at least three hundred people!
Then I got to the nurses' office, sat down, the waistband broke, zipper blew out, and the sides split right open! The nurse gave me a pair of pants from lost property, but to get there I had to walk back across to the other side of campus, struggling and failing to hold on the remains of my pants!
I was given a really horrible pair, so the few people who hadn't seen me could tell what I'd done!