I was married to my STBX-DW life for 6 years. She had twins: Ss(my son) and Sd. The difference between these two was/is night and day. One was cold, manipulative, and rude (Sd) while other was sweet, caring, and respectful(Ss). 

Without going to too much detail, Princess had mommy dearest wrapped around her fingers. STBX-DW gave into Princess's demands because she did not want to be a 'mean' parent. She favored Princess so much that she would ignore Ss. Ss was the sweetest boy I've ever met. He was a bundle of joy. He cared about others, while his sister only cared about herself. I hated my former Sd. She wasn't a good person. Ss was much closer to me than he was to his mother. The siblings hated eachother. Even the family therapist said that they're 'too different'. Before I filed for divorce, Ss filed for emancipation from his mother and then filed for  adoption making me his legal father. 

His mother met his basic needs but she did not met his emotional needs. Even before I came into the picture,  even my ex-in-laws advised my STBX-DW that she is neglecting Ss and only being a mom to Sd.. Surprisingly he never acted out because of this. He focused on things to help better himself as a person. Both of them are 16 but Sd is barley passing grade 11 while Ss is just about to finish his first semester of university(he's a genius). He was given a full ride based on his academic merit. He was also offered a scholarship because of his excelled in soccer. He says that he's grateful that STBX-DW favouring Sd so much over him because it forced him to grow up and mature much faster so he's pepared for the real world while sd will crash and burn when reality hits her.  He refusesto let his childhood have a negative impact on the rest of his life. 

Since STBX-DW and the evil pawn moved out of my house, things have been great. The atmosphere of the house just seems lighter. Ss has thanked me repeatedly for not abandoning him. My family has accepted Ss with open warms. We all love him very much. People have come up to me and praised me for how thoughtful and sweet he is. The credit does not go to me. It doesn't go to his mother. All credit goes to him. He never let the neglect get to him. He opened up to me once abut how he was contemplating sucide when he was younger because he felt like he felt like he didn't belong anywhere but he decided against it because he wanted a better life for himself and the only to achieve that was with hard work and dedication. That speaks volumes. 

He considers himself fortunate to call me dad and I feel the same about calling him my son. 

STBX-DW  contacted me recently saying that she wishes to speak to Ss (he changed his number). I passed the message on to him. I left it in his hands. I did encourage him to have a  relationship with his mom. His answer (Don't remember it word for word):

 There's a big difference between being a mother and a mom. Is she my mother? Yes but she is not my mom. I don't hate her but I need some distance for a while. I don't know about the future but right now I need space, if that's okay?

I told him if that's his decison then he has my full support. He did ask for her number because he wants to tell her himself; I  gave it. 

He turning out to be a great young man. When I was 16, I was an nightmare but he's the exact opposite of what we expect teengers to be. I have told him that if he ever feels like he needs to speak to a outside party to let me know and I'll arrange that for him or to seek the counselling services at the university if he needs too. I know he's going to go far in life.  

I'm very proud of him.