Family fall out over sister seeing my son

[PiscesMama]

Hi,

I really need some advice on my situation with my family. I'm a single parent to my 2 year old, his Dad and family have never been on the scene so it's just my family. When I was pregnant I hadn't spoken to my older sister in about a year, she is quite a bully, she didn't acknowledge my pregnancy, or my son being born, she would visit my parents when we were there and completely ignore us both. It came to a head and I told her that if she wanted a relationship with him, that meant me too and she was to start treating me better. My mum looks after him during holidays from nursery so I kept finding out almost by accident that she had been spending time there then, never making any effort to see us otherwise or see me and my son together. She makes effort with gifts etc so I have felt like I can't say anything plus she is such an aggressive character and my Mum always backs her up.
I just recently booked a holiday for me and my son, which my Mum asked to come on after I booked it. My sister then told me 2 days before we were going that she and her friend had booked the same site and were joining us. I was fuming as I felt like my holiday had been totally hijacked and I feel so uncomfortable with her. I made the best of it and just focussed on my son as I had spent a fortune and planned for so long but it did ruin it a bit for me. I had exchanged a few voice notes with my sister when she had told me she was coming, and in them I was obviously talking about being quite annoyed it had been arranged behind my back and the holiday not being what I had planned.
Skip forward to today, my little boy had a last minute sleep over at my parents last night so I went to collect him and my sister was there. My Dad had told me this morning he was 'just going to the park' which gave me the impression he was taking him. But actually she took him herself. I'm aware none of this might be 'alarm bells' but I've made it really clear to my mum that I don't trust my sister with my son. She is very vindictive, she previously had a step son who she lost when the relationship ended and she never had children, she spat at me during a row when my son was just 6 weeks old that I 'don't deserve him' (because she had lost her stepson) and I've just always been so worried that she might do something to my son because she is so spiteful. She is very manipulative and it really works on my mum; I can see through it but I can't beat her at this game because I am an honest person and I get frustrated at other people when they can't see it. So today I saw her at my mum's and I did go in and say I'm annoyed again that you're all sneaking around again, first the holiday and now this, why do you have to only come and see him when I am not here etc.
My Mum of course came straight down on her side and said she will not stop my sister going to her house, even if my son is there. I said I understand that but I don't want her around my son. For context, she has also been calling him things like 'a toad' 'weirdo' 'ratbag' and he is walking around saying 'im a weirdo' and getting upset when I correct him. She is not an influence I want in his life at all. I don't know how to maintain a relationship with my family, let my son maintain that relationship and not have her be in his life. I feel like the more she is in life the more damage she will do. I also can't have it get to a point where she is poisoning him against me for example. He is 2 at the moment and adores me, but I know what she is like and I wouldn't put it past her to slag me off to him as he gets older and as I am a single parent, I haven't got anyone to back me up against it.
I don't trust her and if I needed any more proof that I can't, she sent voice notes I sent her about my mum coming on holiday, to my mum (out of context) to make my mum think I didn't want her there. So she was just trying to stir things up and damage mine and my mum's relationship - and it has worked because we aren't speaking now, and my mum thinks it's my fault and my sister is an angel. How do you win against people like this?
My mum has my son in holidays so I can ask the nursery to extend his contract which will mean my sister will have no option to keep sneaking round to see him when I'm not there, but that will definitely cause more trouble between me and my mum.
I've said to my mum that she isn't respecting my wishes as his mum but she just fires back at me that she is also her parent and is welcome in her house whenever.
I feel so lonely and stuck - I know it's a long post but appreciate if you have read it!

@PiscesMama You are doing a great job as a mum in a really tough situation. I agree with PP’s- your sister and mum won’t change. You sister sounds vile and your mum won’t hear a bad word against her. It sounds like your sister always has to have an enemy and you are the current one, she’s probably jealous of you too. Does she work?

You have to pull back. Get your son into nursery instead of at your mums. Try and make more mum friends (I know it’s hard) to build your own community away from them. You also don’t want your son growing up thinking that behaviour and toxicity is normal. If they are the type to turn up banging on your door I’d also think about moving area tbh.

Your only option is to not allow your parents to have your child at their house as they obviously don’t give a shit about your boundaries around your sister.

If your mum blows up, let her.

Toxic family dynamics go way back through the generations and will continue going forwards unless you break the circle for your dc.
your mum is the facilitator, she makes sure your sister always has the upper hand and doesn’t care about your emotions. When you have something to celebrate, she is more concerned with how it affects your sister’s ego. She offers your son up to her like a sacrificial lamb and will laugh and disregard your concerns and rules.
Your dad might agree with you that it’s wrong but will meekly turn a blind eye and help keep up the status quo.
Your sister didn’t demand to be put on a pedestal, she has been placed there, sharing it with your mum. When she hurts you, your mum applauds because your sister is acting on her behalf. The sad thing is, had your mum not created the dynamics between you all, you might have had a loving sisterly relationship. Your sister shows her true colours but your mum is exactly the same but hides it well. Your mum had to ensure she is top of the food chain and both she and your sister are the only two allowed to rule over you all, any cries of ‘it’s not fair or keep my son safe etc’ are stamped out like mutiny. Your parents won’t come to your house as you wouldn’t allow your sister there and she has to be in control at all times.
Your son is being fought over, they want to rule over him and get him to obey only them, he is your replacement scapegoat. Any boundaries you put in place are disregarded as they don’t respect you or even care, if you try to stand your ground they crush you.
They will punish you for enforcing your son’s safety and wellbeing, in their eyes they haven’t give you permission to be important enough to have rules in place to protect your son.
When you change his hours at nursery, you will have to warn the staff that, unless the staff have your permission beforehand, no one but you collects him and if you do have your mum down as a trusted person, then she is only allowed to collects him at set times/days when you inform them beforehand.

The family member who calls out the elephant in the room and won’t be silenced, is regarded as the trouble maker, I’m very proud to say I’ve always been labelled that!
When you have been disregarded and dismissed all your life, you have to stand up for yourself and allow yourself to be important in the face of ridicule and anger. If they walk away then you lose nothing because you were always on the outside looking in and had no family looking out for your best interest anyway. Be aware, these toxic dynamics have been so ingrained in you that you may repeat them on to your DC and GC, you have to become very self aware in the future.