To have nothing further to do with them?

I didn’t have bridesmaids, my husband didn’t have a best man, we had a wedding with witnesses only.
I also have mum friends, whose children play with my children. Relationships can be hard to facilitate but we also only have one cousin who we don’t have a relationship with, so the friendships are important to facilitate where possible.

I'm also autistic, so you’re reasoning is crap.

A lot of people don’t see cousins as close relatives though.

You say you don’t have any family, but I expect if you checked your family tree, you would find you had second cousins, great aunts, great nephews, etc. Everyone does. But few people have any significant relationship with them because they are too distant to be close to. And in some families, first cousins are similar.

Eh?

I’m not denying social challenges are a part of autism, that would be ridiculous.

My problem is with the generalisation that autistic children rarely get included in social situations because most kids don’t want their friendship. That can absolutely be true but, because of the diversity in how social challenges manifest, it isn’t for others.

The adults I know, and their children, don’t all share your friends’ experiences but they are all autistic.

It isn’t ‘awful’. It’s totally and utterly normal for a seven-year-old’s party to be just school friends. You’re coming across as obsessive and a bit mad, to be honest.

What strikes me most about your post and subsequent updates is that you find managing relationships hard. You are very defensive to any perceived criticism. You say that it's hard to make friends. If that is the case, then likely your defenses are up. If you react or are bristley/on guard with others, then they will respond/counteract. You will then use these responses as 'proof' that people are not to be trusted. When self esteem is low, it's common for people to blame others rather than reflect upon their own role. You say that you are ND. That being the case, that will make it harder to pick up the subtle communication cues. I really think that it would help you to reflect upon the way that you interpret the actions of others and how you respond. You clearly want to have good relationships, but I suspect that your communication style may well be inhibiting this. A few tweaks could make a big difference.

YANBU. I’d be hurt and pissed off too. I’d also be doing one last text to the group chat and tell them exactly why I’m cutting them off and why I absolutely won’t be looking after their child so they’d better change their wills.

I meant to say, but got distracted, reading about breaking generational curses might be good for you too, just because your lonely childhood was hard, doesn’t mean your kid has to be lonely. My childhood was horrendous and scary and lonely and chaotic and I’ve done everything I can to ensure it’s not the case for my kids.
I don’t get it right all the time, and they have struggled,,especially being asd and nobody believing me for years.
i said upthread i have no strong family connections so i have made my new little family my family, they will grow and move on one day and then i will find other things and people to fill my time but i dont mope around my kids complaining that our family is so cold and un compassionate etc,
i try and instil better values in my kids and show that we can have fun together and with other people including their own friends they’ve made completely independently of me.
i reiterate that you will benefit from some therapy with a neuro affirming practitioner because you are really doubling down on how much this one relationship means to you all and its not helping you to see the bigger picture

@the7Vabo that's a really good point about siblings too, actually! I've never really thought of it from that perspective (having none!), but I definitely have friends who rarely/if ever see their siblings in adulthood.

Don’t people with autism have mum friends then?

I think it also assumes something about siblings. I have one sibling, we are not close at all. She lives aboard and I might see her twice a year but generally via our mum.
I don’t expect to have any significant relationship with her as we age. I’ve always been much closer to friends as has she. I find it sad at times, and it’s not something I would want for my own kids, but it is what it is.

But it isn't really wrong. Having difficulty relating to peers and managing friendships is literally one of the main criteria of ASD. Of course people with ASD can and do make friends but it's usually more difficult by the very nature of it. If we're seriously at the point where the definition of Autism is so diluted that we're chastising people for accurately determining one of its main features then surely it's all meaningless?! If you don't want to acknowledge the challenges that come from having asd then respectfully what is even the point of a diagnosis?

I have autism too and I know from experience that building relationships can be difficult.

I know your husbands family have disappointed you but unfortunately you have to accept that this is outside of your control.

I am an only child and growing up was close with my cousin, who is also an only child. Now, as adults, we barely have anything to do with each other. We just grew up into very different people with different priorities (which is fine!). She had a family quite young whereas I've been more focused on travel and my career (I also can't have children but that's another story!).

We're still on friendly terms but maybe see each other every year or two and exchange texts maybe once a month. Other than her, my parents are my only close family, but I'm not relying her or placing any expectations that she exists to someday help me with my loneliness in old age.

She said “I offered to have their DC to stay over the summer and they refused”

I didn’t interpret that to mean for the whole summer, just a visit at some point over the summer.

you DO sound intense and hard work. You may think going off upstairs in a huff and blocking them on social media is a ‘quiet’ way of dealing with this, but it really isn’t. It’s extremely petty and passive aggressive. If you were a joy to be around, people would want to be around you, it’s that simple. So if they don’t want to be around, maybe you are a difficult person. Do some self-reflection and try to model better behaviour for your daughter.
Keep inviting the kids round from school, even if you don’t get an invite back. Don’t look at this as a rejection - some people are genuinely too busy/they have tiny or messy houses and don’t want people over/they are so busy in their lives they just don’t think about returning the favour. It’s not as black-and-white as ‘they haven’t invited me = I won’t try any more either’. Give people the benefit of the doubt and try to be more flexible in your thinking. I understand this is hard to do if you’re ND. If a kid stop coming over, then fine, it just means your children aren’t compatible. Don’t get upset by this just move on.

This is good advice.

Worth pointing out also that it's virtually certain some of the mums and kids in DDs class will be ND themselves, diagnosed or otherwise. They may struggle with social situations too. My own ND child would find this sort of intensity very difficult to cope with.

My thoughts too.
Neither of them had anyone close enough to be in their wedding party.

This is not about being autistic.

This isn’t politically incorrect, it’s just plain wrong. Your limited experience of a few children doesn’t represent all autistic children because autism is a spectrum disorder, affecting people in different ways.

A phrase I hear again and again through neurodiversity networks and groups is “if you’ve met one autistic person, you’ve met one autistic person”.

Also, please prioritise your own family. The whole idea of not spending Christmas together because you need to take the in laws in your car and there's no space for you is, frankly, ridiculous.

I'm guessing your daughter has only one cousin, but the cousin has more than just your daughter (from her other parent's side). I don't think they did anything wrong really. They must have asked the child to keep the party a secret because they knew you'd kick off about it. I had a similar situation with XH's family. His sister had one child and they (not the kid but the parents) would try to hang on to my kids like a leech, even sending birthday cards referring to them as siblings and not cousins. It makes you instinctively push back to be honest. XH would ask our children to hide stuff from them and it used to drive me mad. We couldn't even have a gathering of friends, it had to be a secret from them.

It's important to build friendships with people in your and your children's lives. School friends mainly at this age, but also from clubs and activities. It's not expensive, I've had birthday parties for my kids some years which are just two or three classmates coming home after school for sandwiches and cake.

Other women also have autism and have friends. That in itself is not a reason for you to be excluded by pretty much all other mums.

How your autism presents itself and affects others (as it's different for everyone) may be relevant.

My DD is ND and whilst I haven't had a formal assessment, I believe I'm also ND, but I had mum friends even my kids were younger.

I didn't have loads of mum friends, as I got irritated easily with a lot of them and they just weren't my type of people.

Those with Aspergers don’t have the emotional intelligence that NT people have, so you have to really trust what the people on this thread are saying to you. Whether you like it or not, the facts are;

• cousins/blood relatives do not need to be friends just because they’re related. Friendship is formed on mutual interests, compatible personalities, etc. You may think the girls get on great but your daughter’s cousin may just be playing nicely as she’s told she has to be kind to her cousin - she may not actually want to be friends with her and you can’t force that. I used to play with a girl with Asperger’s as our mums were best friends - I put on a good show and had fun when with her but I was also always happy to leave, she was exhausting.
• you DO sound intense and hard work. You may think going off upstairs in a huff and blocking them on social media is a ‘quiet’ way of dealing with this, but it really isn’t. It’s extremely petty and passive aggressive. If you were a joy to be around, people would want to be around you, it’s that simple. So if they don’t want to be around, maybe you are a difficult person. Do some self-reflection and try to model better behaviour for your daughter.
• Keep inviting the kids round from school, even if you don’t get an invite back. Don’t look at this as a rejection - some people are genuinely too busy/they have tiny or messy houses and don’t want people over/they are so busy in their lives they just don’t think about returning the favour. It’s not as black-and-white as ‘they haven’t invited me = I won’t try any more either’. Give people the benefit of the doubt and try to be more flexible in your thinking. I understand this is hard to do if you’re ND. If a kid stop coming over, then fine, it just means your children aren’t compatible. Don’t get upset by this just move on.
• can you get your daughter into a group based on her interests? To create real friendships she needs to find kids with similar interests to her. Art club? Maths club? A sport? Build your daughter’s confidence and happiness through a special interest and the friendships may naturally grow from this.

It’s not automatically horrible! I was an only child until I was about 10?11? And “horrible” is a fairly strong word.

it’s also normal to differentiate between friends and family after a certain age. My (male, same age) cousin only ever invited me to the family parties. I invited him to the “friends parties”. Did it sting a little? Sure. But I understood and learned valuable lessons about family, friendships and healthy responses to (partial) rejections!

what I absolutely wouldn’t do is hype up a relationship. Some cousins are close as adults. Some cousins aren’t. But let them make that decision! Gently facilitating a cousin relationship/friendship isn’t the same as emphasising its importance to your DC…

I've read the first six pages and your responses OP. I think you overreacted. And I speak as someone who is ND with a ND DC the same age and sex as their cousin (born 8 weeks apart). They also live about an hour away.

When the kids were younger (up to 5/6) then it was full class parties with parents friends and family invited. More the merrier. Kids play along side each other so it's easy to add in extra and it not being noticeable.

By age 7 the DC have their own interests and they had separate parties.

Our weekends are spent at clubs, extra curricular activities and birthday parties for kids from school. We are BUSY.

We probably see in-laws and family once every 3 months, maybe longer.

When the kids get together, they get on for a day or two and then it's enough. They are SO different. One DC is super into football and Taylor Swift and make up / dances. The other DC is into chess and reading.

You can't force a relationship. The DC know the other is there and get excited before they see each other. Then they don't see each other for a few months again.

Ultimately
You owe them a serious apology for your behaviour over the party
You need to chill out

Look, I'm going to be politically incorrect here and address the elephant in the room. You should have mentioned in your OP that your child is autistic (Asperger's). I have two friends who have children with this condition, and they rarely get invited to parties, or to playdates (at least not more than once). Of course, it is difficult to understand and hurtful for the person who has autism or a child with autism, but these children are often not wanted by other kids, or their parents, simply because their behaviour, ways of expressing themselves, etc, is different.
As an example, my friends children do not mingle easily, tend to disrupt games, and often provide answers or comments that are considered rude by the majority of people. Thus, they do not get invited to playdates or birthday parties.

I think the best course of action would be to work on improving your child's (and yours) social skills. Blaming others for not accepting or being unfriendly to neurodivergent people is not going to help. This is a reality, and while you may find some who are willing to be friendly and make efforts to befriend you and your child, most will not. Social skills and communication can be improved in those with Asperger's, and you should work on this in order to improve your chances (and your child's) to be accepted socially. Sad, but true.