I don't ever want to see him again, but If I could tell him things, I guess i would say this:

Why? Why did you do that? I know there was no real letter and you weren't posessed by a ghost, so why would you do that to me? I worried about your safety and my friends safety, I took the abuse, the insults, the fear, I took it all to keep all those I care about safe for what? To find out that you had been the one behind it all along? Did I even do anything to make you have to test me like that? No. It wasn't even a test. It was a sick game joke to you. You said it was just to make sure that I wasn't going to cheat on you and that it got too far, but how Am I supposed to believe that? I don't believe that I did anything to make you doubt my loyalty. but then again, who knows. All I know is, that you have hurt me like no one else has, and I'm glad to be rid of you.
Even though I think you are the person I dislike most in my life, I still wish you the best in the future. I hope you grow up and learn to take the blame for your own actions. And i hope you realize that you were in the wrong when you sent me those things; those words that have been burned into my psyche. Even though you're a year older than me, I hope you grow up and mature. Become a better person for the next person you end up with. Because they do not deserve the you that I got.

Sincerely,
You know who.