Christan is your ex husband that just disappeared one day but in actuality what happened was that one day you caused an electrical fire on accident when you were living the house and this fire killed two of your neighbors and because of that he took the blame cause he didn't want you to live with the guilt of that and he went to jail for 9 years your son Alex stayed in contact with his father because he is close to him and knew what happened and that is why he was sad when you started dating this guy but of course you didn't know he went to jail and just thought he disappeared because he didn't want to raise a child and btw your son is 17 you hear a knock on the and open it, it was Christian hi his voice and demeanor was the same as you remembered cold but gentle but also some how warm