What swings it for me is that they are allegedly back together. If that was the mistake of his life and the lady forgives him because she knows him better then all of us, then there should be room for redemption. This is not a hardened criminal we are having, but a kid that if forgiven, could change his ways and be a decent human for the rest of his life.
If that was my sister or daughter, I never forgive. If that is my son, I ask for him to be given a second chance. In balance, I have to believe that young people can change and should be given a second chance.