Is this wrong?

So my mom haves sex in front of my little sisters. They sleep in her room. They don't have their own room and they are really young. One is almost 3 and the other is 4. My mom and her boy friend are always so annoying it grosses me out. My mom doesn't even like her boyfriend. He's abusive. He doesn't pay bills he's almost 10 years younger than my mom. He drinks, comes home drunk. Smokes in the house. He doesn't even care about his daughters. When his first daughter was born he didn't want anything to do w her. But then he thought it was ok bc he had a place to live. I sometimes feel like my mom is being forced to having sex w him. But she doesn't say anything to not get him in trouble, it's what I'm thinking. Her bf is always like "kiss me so your daughter will be annoyed" in front on me. He grabs her inappropriately and she doesn't say anything bc I guess that she thinks its completely normal bc he lives in her house. He's the father of my two little sisters. I have seen my sisters humping each other and laughing as if it were a joke. My mom gets mad at them but they don't know what that is. Sometimes I want to confront my mom and tell her to get some help. She told me like hundreds of times that she was going to kick him out of the house. They have been living like this for 7 years. I'm so sick of both of them. My mom has talked to him about him leaving but he refuses. One day my mom will be completely fine w him and the next she will be mad. But what bothers me the most is that she's having sex in front of my little sisters and i don't feel like that's right. If I take my sisters away from them, her bf will be annoyed and is all like "you can't take my daughters away" and I always want to slap that bitch. He has been with other woman before. And he has a child w my aunt. This family is fucked up. His daughter is older than my sisters and me. She lives with her mom( my aunt). Since then my mom and aunt haven't gotten along. Her boyfriend honestly ruined everyone's life. I hate him so much.

We had social workers and therapists already but the case is closed now. We tried to get a restraining order against him but failed. I don't know what to do anymore. I need some advice on this.