8 year old cousin stabbed my 300 dollar All in one computer when I refused to let him use it.

So.. today my 8 year old cousin was visiting my house. He was walking around the house when he noticed that I had a pc. He instantly started asking me if he could use it, and ofc i said no (Simply because I dont want him installing any viruses on my pc) he asked me again, and again and again until he finally just walked over and started trying to use it. I quickly unplugged my pc before he could modify anything. He started screaming and crying. My mom and his mom came over to see what the heck was going on. I told my mom what he was doing, and she told me to let him use my computer because I should be "sharing" my stuff with an 8 year old, lol. My mom eventually told me that if I didnt share with him, she would take my computer away from me. I said "Fine ill let him use it". I plugged it back in and left the room. Not even a minute later he came out to ask me for my password. I told him that I wasnt going to give it to him. Then he stormed back into the room and picked up some scissors that I had out and started violently stabbing my computer screen until the scissors literally got stuck in the screen. His mom offered to give me money to get me a new computer but my mom told her that I didnt need it since I own multiple computers. Now ill need to save up for a new one /: