Forgiving someone’s sin against you without them asking for it and truly tepenting is not the behavior of a Christian.
Sorry, but I have to disagree with you. As Jesus hung on the cross, He said, “Father forgive them for they know not what they do.” They never asked Him to forgive them. The same with Stephen, who was the first martyr. He echoed the same words, so, I think you error in your assessment of Christian behavior.
Forgiving is often misunderstood.
Forgiveness, really, is NOT for the benefit of the person(s) being forgiven.
Forgiveness is for the benefit of the forgiver.
Forgiving someone who has wronged you removes that seed of bitterness from your heart, allows you to refocus yourself, says you trust God by giving the issue over to Him to deal with.
So, where does "Father, forgive them .. they don't know what they're doing" fit into your understanding?