Basically this has been a fight between me and my SO since we've met. It makes me feel like a bad person sometimes but then I came across this site and it made me realize I'm not the only one. So might be long but here it goes and any advice is super appreciated. His daughter the one who is causing issues is 7. I also have two of my own boy who is 8 also autistic totally getting better basically almost acts as if he is not and a daughter who is 11 totally independent and wants her own space. Then we have a 8 month old son together. So we met 3 years ago his daughter was 4 even then she was showing behavior issues at that time there was no custody agreement so he ALWAYS had her. It would cause problems because I would drive an hour to stay nights on my days off and all of a sudden she would be with him last min and I felt almost robbed of our time together. Which I tried to understand but he HAD to lay with her and rub her back to sleep which I also tried to understand but left no time for us. So fast forward I get pregnant we move in together. Now he has her every Wednesday and every other weekend. Except she is a major brat every adult in her life gives her what she wants to shut her up. A few examples of why it's so irritating. 

So we take all the kids to a hotel on a friday come home next day. The kids had so much fun and here comes his daughter begging to go to his moms her grandma. He tells her no he wants her to spend time here she always wants to be there because she runs everything there. So she has her own phone she calls the grandma hyperventilating crying screaming her dad is so mean all he does is yell at her, hes not allowing her to come over. So his mom is now involved telling him he has no right to tell her no she cant come there. So whatever grandma picks her and my daughter up to go there. He starts getting texts shes scared to come back because all hes going to do is yell at her. Which is a lie totally trying to get her way to stay there. Shes constantly lying now to get her way whenever she wants. 

Another one... she wants to take my daughters art set to school because she doesn't have one. My daughter says no its mine I got it for Christmas. Mind you its bedtime and they are laying in bed arguing. I then tell her no she could care less... her dad comes in tells her no she goes crazy saying it's not fair she doesn't use it. So because of everyone telling her no she stays up until 3am lying and crying her stomach hurts waking up my 6 month old at the time not caring. She literally cannot handle when someone tells her no. They wake up for school my daughter comes in that shes putting in her backpack taking it anyway so now shes stealing ! I tell her no take it out she goes crazy now not wanting to go to school. She comes back next time shes here BRAGGING she got the same one and she didnt need hers anymore. So someone whoever gave in and got her that after trying to steal it from my daughter.

Two weekends ago shes in the bedroom kicking my 8 year old son. Hes crying again hes autistic his feelings get hurt easy. So her dad goes in she lies says she didnt and hes hitting her ! My daughter calls her out says shes lying shes kicking my son because he was talking while she was on the phone. Totally unacceptable and he just let it go. He said well my son is probably making it worse than it is like uhhh shes hitting !

Basically shes manipulative, lies, wants to steal shes getting worse everytime shes here. It makes me so uncomfortable to even be around her shes just like a ball of dark negative energy just waiting to explode any min something doesn't go her way. 

So now his mom keep her Wednesdays thankfully but every other weekend I dread i hate even being home. I try to tell him they need go fix her behavior before it's too late because shes going to keep getting worse. Her mom is a total crazy person he cant even talk to her so theyll never work on it together and he cant fix her on 4 days a month. I know shes his daughter but it makes me want to just leave and end the relationship or he just let her stay with her mom for good. I dont want her behavior rubbing off on my 8 month old and shes always way too rough with him and has no regard hes a baby. Her dad just lets everything slide and it's super annoying I feel like I just want out of the situation. Her mom is now engaged and I just wish he could sign her over to him when they get married because I cannot deal with a crazy out of control child much longer. Even one day a year with her would be too much

 I feel so cold and just disgusted I feel this way but the fact no one is dealing with the issues and letting her down is just I cant even wrap my head around it. Her grandma acts like shes her mother and makes the rules. When we went to the hotel her grandma texted her how they are going on a fancy vacation for days during the spring trying to one up her own son with his child. Its just all toxic and we fight non stop about it because he cant deal with the truth. 

Let alone he isnt even the nicest to my kids when they do nothing wrong but spend their time alone. My kids are so independent it's like they're not even here. He will call my autistic son retarted just to take it out on him his child is out of control. He tries to hurt me through them because I try to talk to him but he makes it way too personal and ignores it all. 

I wanted to keep it somewhat short but explain why I feel certian ways. Like I said any advice would be nice. Even if it's someone saying I'm crazy haha. I just dont know how much more I can handle with the situation.