Mistakes from the past... never bring those up to your spouse. When you have forgiven your spouse for something they have done once you forgive them that is it, it is done. Never bring it back up, especially if you are trying to use it for your own advantage that is not love.
When you have forgiven your spouse, sometimes that might take longer than other times then you just gotta leave it and trust that God has taken it.
God doesn't want you to hold onto it anymore. So forgive freely and trust in him.