I have been with my de facto partner for 4 years now. She has a child from a previous relationship who is 6. The biological father has spent less than 20 days with the child throughout the entire duration of my relationship with my partner. His care factor has been non-existent until recently. Due to external motivations, he has decided to take us to court in order to see his child. I hate saying his child. He is my son. Unfortunately, due to the system being how it is, there is no way that we can keep our child away from him. My question is: If I were to marry my partner (it's on the books) would I then be able to adopt her son, legally making him mine and giving her douche of an ex no rights under family law? Please help if possible Thanks.