I got sent off in a hockey game in a PE lesson when I was 14 or 15 - my best friend and I had been talking about how annoying the teacher was, screeching at us to 'tackle, girls, tackle!' and how funny it would be if someone went rogue and actually properly tackled an opponent.
So next time my friend was whacking the ball around with her hockey stick, I did exactly that - absolutely copybook tackle too, 'cheek to cheek' and slid down around the bootlaces. We were all laughing hysterically; the dragon lady PE teacher, not so much...