This is justified isn't it?

This guy I liked called Aron acted like he liked me, he would smile at me a lot, always spoke alot to me in class and he told my mum he thought I was special. I tried to kiss him the other day at school and he totally freaked out knocked me back and embarrassed me after leading me on for a year and now I find out he has a girlfriend after I saw him getting into her car, so I followed them to her house and tonight I'm going to mess with her car and leave her a little note telling her to stay away from him. My friend Zoey says that this is over the top but I know he likes me, but the problem is the other girls, he talks to them too, I suppose he has to because of his job as our teacher but still I wish it was just me who he taught, all the other girls know he belongs to me though, after I saw this girl called Tiff laughing with him and I put coke in her locker which got her expelled and after Jenny had her little accident down the gym stairs, it's just his girlfriend who needs to learn. But he's mine so thats okay isn't it?