Forgiveness doesn't mean that something didn't happen. And it doesn't mean that you can trust someone.
And really, it doesn't matter whether he believes you forgave him or not. It sounds as if he wants you to forget as well, and that can be impossible most of the time. It also sounds like he doesn't want any ramifications for his past actions....if he is truly sorry, he would expect and accept those.
He must think that you left in order to punish him. He might not "get" that you left because you had no other choice in your respect for yourself.
You could leave him the time you forgave him, because you let go of him and his deeds from inside your heart. He simply cannot understand this because it came as a shock to his system, and his ego. It really does not matter what he believes, it matters how you feel. Hope you feel free. :)
You say you have forgiven him and only you know the answer to that but you have obviously chosen to move on. This is a seperately issue but I can see why he thinks you haven't as in his mind you would still be together if you had forgiven him.
Explain your reasons for leaving or cut ties
He still can't believe you left him. This man is too stupid and arrogant to realize that you probably had to leave him for your own sanity. Forgiving him doesn't mean you should allow his behaviour to continue. Don't let him in your head with his bulls***t. Sounds like you're well rid.
Sounds like he lives in denial. If you left, why do care what he thinks anyway.