To forgive or not forgive

Cheating is an absolute NO for me which I've clearly made it known to my husband right frm the start when we were dating. I've experienced how traumatic it was to have a father who cheated and married another without my mom's permission. Although their marriage miraculously lasted till now as he had divorced the 3rd party, our family's trust in him is lost and we find it almost impossible to forgive. Cheating isn't just a mistake, it's a deliberate choice!