Busted for Pranking Mr. Johnson

So here's the deal, I pranked my history teacher, Mr. Johnson, and got caught. I put whoopee cushions on his chair before class started. When he sat down and it went off, he nearly had a heart attack. The whole class was in stitches. He finally figured out what happened and made me clean every desk in the classroom with a toothbrush as punishment. Not my finest moment, but hey, I got a laugh or two.