When I was in high school one thing I would do is any time a teacher would put on a movie and leave the room I would go over to the computer and just skip to almost near the end and it would end and the teacher would say huh I thought that was longer, well did you guys get what that was about/did you like that video? And people would be smiling and like Yes and then we would just get to have free time usually afterwards if the video was supposed to last the entire class, and no one ever told on me. I remember doing this in Algebra twice my senior year and skipped these boring math vids when this boring strict creepy teacher we all hated left the room just momentarily and most of the kids in there were younger than me who I didn't really know, including like ap freshmen.
I have what might be a false memory or dream but I think really happened of the teacher getting back and catching me touching the mouse but the vid playing and he was like wtf and I said "oh it stopped I was just hitting play" bc my seat was the closest to the computer and just sat back down and nobody said anything.