My SO's step dad emotionally abuses and manipulates her, her sister, and mother. I see it and have pulled her to the side to explain what he is doing is wrong and they shouldn't feel bad about anything he is saying. One example he and his wife got into a fight. He was watching the youngest daughter who can't take care of herself yet while everyone else was at work, packed a bag and told her he was leaving and it was all her moms fault. She called my SO and her mom all three of us left work to go and make her feel better. She texts him we're all there. He comes back says he forgot his wallet then starts yelling at his wife in front of all of us. My SO begged me not to say anything but I did, I stuck up for the mom when he was trying to overpower her and interrupt her and I stuck up for the girls when he tried to drag them into it to pick sides. The wife left and he tells the girls why didn't you stop her. He blamed my SO for not doing anything to stop her mother from leaving (pretty much holding her against her will is what he wanted) I interrupted him calmly told him that was wrong and pulled my SO outside. She began crying and I explained that its not her job to fix their relationship and that he was trying to manipulate her and make her feel bad. Later on that day he goes to his wife's work tries to block her car in and yell at her in the parking lot. My SO goes over and he yells at her.... 

This all happened like a month ago and it only took a week for it to all blow over like nothing ever happened. He constantly manipulates them to make them feel like shit and they don't see it and actually stand up for him. I don't know what to do. This is a big issue in our otherwise great relationship.
user
Step dad emotionally
assistant
My SO's step dad emotionally abuses and manipulates her, her sister, and mother. I see it and have pulled her to the side to explain what he is doing is wrong and they shouldn't feel bad about anything he is saying. One example he and his wife got into a fight. He was watching the youngest daughter who can't take care of herself yet while everyone else was at work, packed a bag and told her he was leaving and it was all her moms fault. She called my SO and her mom all three of us left work to go and make her feel better. She texts him we're all there. He comes back says he forgot his wallet then starts yelling at his wife in front of all of us. My SO begged me not to say anything but I did, I stuck up for the mom when he was trying to overpower her and interrupt her and I stuck up for the girls when he tried to drag them into it to pick sides. The wife left and he tells the girls why didn't you stop her. He blamed my SO for not doing anything to stop her mother from leaving (pretty much holding her against her will is what he wanted) I interrupted him calmly told him that was wrong and pulled my SO outside. She began crying and I explained that its not her job to fix their relationship and that he was trying to manipulate her and make her feel bad. Later on that day he goes to his wife's work tries to block her car in and yell at her in the parking lot. My SO goes over and he yells at her.... 

This all happened like a month ago and it only took a week for it to all blow over like nothing ever happened. He constantly manipulates them to make them feel like shit and they don't see it and actually stand up for him. I don't know what to do. This is a big issue in our otherwise great relationship.
user
SO's step dad
assistant