i locked the music teacher in the music cupboard once. she was bangin on the door going "let me out, this is outrageous, who's done this" i ran away, round the corner of the corridor, headlong into another teacher who quite obviously put two and two together hearing the commotion in the background. still makes me smile and im all growed up now. i dont recall getting into trouble, in fact i think the teacher who caught me found it a bit amusing himself, but obviously couldnt let me know that!
i did the same we had an idiot history teacher who would leave the keys in the door and as i sat closest i would lock it, he knew it was me but i never got in trouble, i think it was because i got egged on by the rest of the class!