The sweater

You actually manage to make it through first period Social Studies class without an "accident". You just couldn't find an excuse to lose anything. Already off to a poor start today. Oh well, it at least lends credence to the idea that you're trying your bestest to stay clothed today so it's not a total loss. Luckily, the next class is Robotics and that should give you some opportunities to do some real damage to your outfit. The school may recommend that you transfer to a different class if you're too clumsy for Robotics. Not as an insult to you but just so they don't end up with you being hurt. You know exactly what you're doing but they don't know that. Also, whole the solder trick is definitely still usable in a pinch, you'd really prefer to find a new way to lose clothes. And you find it.

While the student next to you isn't looking, you hook a loose thread onto his winding machine and let it go to work. As he's talking to the teacher, his robot stars unraveling your sweater. After two minutes it's almost completely undone. The teacher notices and yells for the student to stop his machines but it's too late by the time he gets there and what remains of the sweater falls off of you, having no more structural integrity to hold it up. The teacher lectures the class about not leaving their machines unsupervised.