My older sister has been with her boyfriend for almost 2 1/2 years. They have a son who is almost 2. He has three other kids that he never sees. His story changes when he explains why he doesn't get to see them. He has openly admitted that he didnt have a job for the longest time because he didn't want to pay child support. Now he does work and he only brings home 200 after child support. My sister pays all the bills so this 200 is supposed to be their emergency money. He spends it on cigarettes or alcohol. He is an alcoholic and refuses to admit it. He is emotionally abusive to my sister. He has thrown stuff at her and has tried to take his son away while having alcohol on his breath multiple times. They all live with my parents and he is not allowed to drink in the house. Multiple beer cans and bottles of whiskey can be found hidden in their room. My sister has a rough past...she got married to fast and divorced 6 months later. She was stuck with all the bills. She went down hill...going to the bar often. She met the boy friend there and after he went to jail then got out they got together. They have moved in and out of our parents house three times. They live here now. I was gone for a year and she would call me crying about what he had said to her and how he treated her. She wanted out of the relationship but stayed because her son needed a dad. This past weekend...a huge fight broke out and the cops were called after he tried taking his son with alcohol in his system. He insulted my sister and our family. He called her a horrible mom and said she was never going to be able to see her son again. Once the cops showed up his attitude changed. My sister and him agreed to seperate and she got her son back. He was picked up by his niece and left. My sister has messaged him since then all the time and he is saying that he didn't mean any of it and would stop drinking. Something he has said before. My sister has decided that she is going to have to decide between being with him or our side of the family. She is going to choose him and we all know it. She knows she is being emotionally abused but says hes the only one who loves her. Ive seen their messages and he manipulates her. Even though she openly admits what he does she goes back. I am afraid the emotional abuse will turn physical. He has thrown objects at her before. I am afraid I will lose my sister and my nephew will end up in foster care. What can I do to help my sister?