If the male wants to do whatever is objectively best for the female regardless of the impact it has on him, should the male in this scenario not pursue a relationship with the female altogether in order to avoid the heartache she may undergo while struggling with his past?
This is not really an issue of objectivity. If this particular matter is of great importance to the potential bride, he needs to reveal it, but briefly and without much detail. Spouses are not required to confess to each other, but also should not conceal matters of importance clearly articulated. There is no way to undo someone's past. However, it is a choice for each one personally to make of whether to let go of another person's past iniquities or not. Just do your part according to your Father Confessor's guidance, and be willing to accept the outcome according to God's will.