I don't normally hold a grudge, but of course there are exceptions to every rule. If a person, by their words or deeds, causes harm of any form to another, then that is unforgivable. I have 2 such individuals in my life that have done precisely that, and they will never be forgiven for the untold misery that they caused, and as far as I'm concerned, they don't exist. And no - my ex isn't one of them.