To hate my partners family

[Cheeselover23]

There is a long back story to those so apologies. I'll start with the sister but his mums an issue too.
I've never had a good relationship with his sister, and have known her for four years. She stole around £20 from me in one go and then a couple weeks later used a tablet a friend had lent me and spent around £6 on it on apps. Her mum paid me back the £20 but I never saw the app money. Not as big a deal but she also steals my food and alcohol that I have there (usually order a pizza and then leave some for the next day but she'll take sone either without asking or takin more than she asked for). She'll then lie about whatever she's taken.
She then tries to make me feel awful by saying she preferred my partners exes or saying he was a lot happier with them.
On Saturday I broke down going to their house and had to walk back as my phone died. I bumped into her as I went through the village and she called her mum saying I'd broken down and karmas a bitch all whilst laughing.
My nan died recently and I mentioned how one of my family members would soon be celebrating their first birthday without her there to which she replied "oh no one less present"
So many other things have happened with her but these are the ones that really stand out.
I used to have a good relationship with my partners mum but recently I fell pregnant. I then started to realise that actually the people who had been trying to warn me of how awful she is were right. She said she'd give the child food to make her the preferred grandmother, told me I would use a dummy even though I told her I didn't want to, tried to change my mind when I said I wanted to breastfeed. She also offered to convert one of the bedrooms into a room for me, partner and the baby which obviously sounds lovely but I now realise was an attempt to keep her son close and to be over involved with the baby.
I actually lost the baby towards the end of April and she's been very insensitive despite having had two miscarriages herself - one of which is so painful for her she won't even talk about it. She's now tagging me in Father's Day things which I actually would have bought had I still been expecting but now are just so hurtful to see. I haven't outright said it's painful to see these things but when she was talking about it even a blind person could have seen I was uncomfortable and didn't want to carry on the conversation - I'd have walked away had we not been in a car.
And when my nan died I was at their house when I was told. We'd planned a bbq the next day already, and she said "it can be our celebration of your nanny's life". Which again sounds lovely but she never knew my nan, she's only ever spoken to my mum and that's been maybe three times so how could that family possibly celebrate her life.
I'm totally prepared to hear I'm being unreasonable about this or why I'm feeling so angry at some of these things but am I unreasonable to hate these people, and to want to leave my boyfriend because of them?

I should think his mother is trying to keep him at home because she's a grown up and she knows that the last thing he needs is to be 19 and playing at families. Sorry, op, but I have children your age and that's exactly what my mindset would be. There is a whole world out there and so much life for you to taste before you become a parent. It's yours to take. What you're describing here is teenage melodrama, you all need to grow up before you even think about parenthood.

Flying elbows yes I agree with your statement usually, but as I said before, this woman has always wanted him to be "playing families". She was more excited about this baby than we were as she'd been talking about it for four years. I truly believe she isn't doing anything with her sons best interests at heart

And to whoever said I was doing the "pick me dance" I did not. I said I couldn't take much more of his family to him. He then proceeded to have a massive rant about how his family treats me and himself and then came to the decision to not talk to them ever again as soon as possible.
I rented out a room in a flat for six months last year, and I quite happily was no contact with them the majority of the time, just popping in every now and again and he chose to practically move into the flat and he was the one who would always say he didn't want to go home because of how it is there. Of course I don't want him to cut his family out of his life if at all possible, he's come to this decision by himself. I know how awful it is not talking to family because unfortunately I was absolutely no contact with my mother and so in turn my siblings for four months after being kicked out and things getting twisted. I'd love to be able to think his sister could grow up but honestly she seems more immature than an average 13 year old and nastier than an average hormonal teen (believe me I thought I was an awful young teen going through puberty until I met her, now I'm practically a Saint next to her). I'd love to think his mum is a woman doing things to make life for her son easier but it's all purely selfish.

OP - if you are going NC with his family (and you can, even if he doesn't) that's fine. I am NC myself with my selfish father and toxic sister, so I know what's involved.

IF you want to have a go at living together, again, fine. But please, think long and think hard about getting pregnant. Or getting married, just because. I know I changed so much between the ages of 18 and 25 - I just woke up one morning like another person. Your whole life, values, wants and aims change. Please don't even think that you have to live with this bf for your whole life. (Unless you have kids, in which case everything changes. Not least your relationship with him, and with his mother - would you want her as a grandparent? if not, walk away now)