In my school we were going to do a presentation about English grammar and it's meaning etc. They selected groups of two randomly so you could come with anyone in the class. I have very good grades in English but unfortunately i was selected to be with one of the worst students in the class (let's call him Chad). Chad didn't want to do any work and just played games during the lessons when we were supposed to be working. This was fine since i'm pretty bad at working in a group and i like to do my works solo. But when i got done with the entire presentation and started to memorize it Chad got up and started talking to the substitute teacher. I couldn't hear what he said to her but after he was done talking to her she said that she would talk to my real English teacher about my behaviour. I asked her what i had done wrong and she said this ''if all you want to do during the lesson is to watch videos and not help your group you can get out of my classroom''. I got so shocked by this i didn't even know what to say, i got angry and confused at the same time and when i tried to explain that i had actually been working this whole lesson she said ''prove it''. Then i proceeded to show her the edit history in the document. To my surprise Chad had edited my entire presentation and deleted all the previous saves in the document so it would seem like he had done all the work. By this time i knew the teacher wasn't going to believe me so i kept quiet the rest of the lesson and planned my revenge. I re did the whole presentation since he kicked me out of the old one and memorized it and everything. The next week came and we were preparing for the next period which were gonna be the presentation. Then Chad went to the bathroom and left his computer wide open for anyone to do something to his precious presentation that I wrote. I copy pasted a lot of fucked up porn into his document which the presentation text was in. I made it so all photos would appear when you press start on the powerpoint document but invisible if you didn't start it. So the next period came and it was Chads' turn to do his presentation. Right when he started the powerpoint all that could be seen was that porn i had put in, and when i say fucked up porn i really mean it. Everyone started laughing and the teacher's face was red as a tomato. He got suspended for a week and after that everyone judged him because of that incident. After all this i felt kind of bad and i think i went a little too overboard. So guys what do you think am i the asshole or was this justified?