To have nothing further to do with them?

OP, do they know you didin’t turn up in the past because of the car situation & not fitting in w PIL & your kid?
or could they potentially believe you don’t like them - don’t want to see them but WILL eg host their kid, take her on holiday etc, but just not see them?
If that’s the case, a conversation could probably solve all this out?

So it's not all about you or your daughter?

Your SIL hasn't seen her brother or her parents for a while either.

Don’t be so pathetic

I imagine the party was largely for school friends/classmates who all know each other. Your child would only have known the cousin by the sounds of things. Them being there could have changed the whole dynamic and meant the party child not being able to interact with friends.

Having cousins is lovely when they are small but it’s not unusual for them to grow apart when they get their own friend groups.

A sensible idea would have been to let the party issue go and maybe ask your DH to have a word with his sister about the other stuff.

Reading between the lines it looks though that you are forceful and controlling and they are trying to step back a bit.

you only reply to agree with you, but WHERE did you get they are excluding DIL to seeing their grand-daughter?

clearly they haven’t invited PIL.. because it's a kids party for 7 year old? No one invites grand-parents to THAT 😂

Keeping the party a secret was shit of them though
looking at how you react, it sounds very wise..

From the person who
never invite the cousin to a birthday party
refuse to go and visit at Christmas because "the car is too small"

Get over yourself. You should put your child first, and you are making it all about you, it's not fair. It's not fair on your husband either.

To be fair, here the grandparents are excluding themselves by insisting on your DH giving them a lift. They could get a taxi or public transport. They shouldn't be sitting passively waiting to get a lift to see their grandchild.

So my dc has 1 cousin who’s two years younger than him. When they were babies/toddler's we did family parties and vice versa . Once they got to school we did a party with school friends and then had a birthday tea with family and sil/bil did same. They don’t go to the same school, they live an hour apart it’s easier to keep them seperate but the cousins love each other to bits. It’s a totally normal thing to do.

OP none of us here can tell you why your child's family are doing anything. We only have your perspective to go on so all we can do is speculate based on your behaviour that you tell us about and the language that you use.

If this is the way you behave and overreact frankly you and your child will continue to be left out because I wouldnt want to spend time with you or want my child near yours when you are such a drama llama

OP why not ask the question ‘why was my DC not invited to the party? ‘

You may be surprised by the answer and it’s the least that should be done before blocking and going NC with family, particularly as family seems to be important to you.

Why have you got such an emphasis on family being more important than friends? Why should your child be more important than others hes actually friends with?
Why are you trying to force this situation so much?

Honestly OP you sound like a nightmare and I'm not surprised they dont want to leave their child with you or encourage a close relationship. You're upstairs swearing having a meltdown like a toddler instead of just talking to them.

You are your daughter’s worst enemy. Unless you start behaving like a rational human being, and allow a friendship between them develop naturally (or not, as the case may be) I can guarantee that they will want nothing more to do with you.
It is you who is sabotaging your daughter’s chances of a normal relationship with her cousin. It is you who is modelling terrible social and conflict resolution skills for your daughter.

Sorry OP but this. You're embarrassing yourself and, by extension, your daughter.

Children's friendships can't be mandated or choreographed and just because people are family they don't have to like one another.

It's hard to know for sure what's happened or not between the children and whether this distancing has taken place because the cousin wants a bit of space or because the parents find you overbearing and entitled. You've very clearly pushed and pushed and failed to read the room when the parents wanted to take a step back. Maybe they got fed up of feeling they couldn't get away from you. Maybe their DD got tired of having your DD imposed on her.

It may be a bit of both. But if these children are going to have a genuine, life-long friendship it has to be on their own terms.

If you want to salvage any hope of allowing these children to remain friends, please for your daughter's sake take a step back.

Oh come on if they died surely you wouldn’t refuse to have their DC, it’s not their DCs fault.

If there was a limit on numbers then I think it’s fair to choose friends who they see regularly over a family member they haven’t seen for months. Keeping the party a secret was shit of them though, if they usually invite PIL and didn’t tell them about it then it does seem like they didn’t want your DC there (if it was due to limited numbers I think fair enough but they could explain this).

I don’t blame you for not wanting to bother with them in the future though, just stop trying to arrange things and leave them to it.

Maybe you are not evaluating the relationship in the same way they are. My dd would be polite to her cousins but really didn't like them because they could be unkind to her once adults were not there.

Probably the best thing to do is to let it slide a bit and see what happens in the future. Going nuclear could damage things for good. This is about your ds, not you.

Does your husband put in much effort with his sister?

If not then you trying to force things/change the dynamic was never going to work I wouldn't have thought.

what a charmer you are

It's your own child you are punishing. The more you post, the more we can understand why they are walking on egg shelves around you, and not getting too involved. You genuinely are exhausting.

What a ridiculous thing to say. I have Asperger’s and have always had lots of NT friends who have accepted me as I am and treated me absolutely normally (just as I like!)

Why so rude about NT people?

Honestly don’t worry about the only child cousins thing. I’m an only and my Mum was always desperate to foster a relationship between me and my cousins for the same reasons as you but I wasn’t having any of it, even as a small child! As a very much grown adult now I feel completely fine with no
”blood” family in my life.

Same, it's very much a way to centre op and take the 'focus' of the day away from birthday child.

Are you still sulking upstairs or have you gone down and not completely ruined your DN tea party?
I would complete cut you off from this. And your foul language isn’t doing you any favours either.

Honestly, you need to take a breath, @Pouticel.

But when you say “they” can all fuck off, doesn’t that include your DH? Because he does sound like a big part of this.

It sadly does seem that your BIL/SIL have distanced themselves from your family. I ask this in a kind way - you mention that both you and your child have Autism. Is there any behaviours that your child displays that could perhaps make your BIL/SIL not want their child around yours? Unfortunately, not everyone understands Autism, and if a child behaves in a different way, it can make others uncomfortable and wary. You've clearly tried very hard to have a relationship with your BIL/SIL and you have been pushed away. My honest opinion, this is a situation where your husband should be asking his sister what is going on. Your BIL/SIL didn't tell your PIL about their child's party, because they didn't want them telling you. The situation isn't just effecting your family, but also your PIL. It's all very well your husband ignoring the issue, but all he's doing is burying his head in the sand. You are angry, and I don't blame you, because you don't understand what your child could have possibly done to be shunned. Your husband needs to take the bull by the horns, and speak to his sister on her own, in a calm manner. If there is an issue, how can it be resolved if your SIL isn't honest or your husband doesn't ask???!! If your husband won't ask, then for your child's sake, you need to calmly speak to your SIL. I'm an only child myself, and have a lot of cousins, some I am closer to than others. All were invited to my wedding, as not having siblings makes my cousin's more special to me. However, my son is an only child, and he has 4 cousins - 3 older female cousins and 1 male cousin who is a year younger than him. I'd hoped my son and his male cousin might have been closer, but it hasn't happened. My BIL/SIL have never been bothered with my BIL's siblings and families. We've had to just accept that's the situation.

Omg. You sound exactly like my brother. Huge huge over reactions to perceived slights. Then struggles to back down.

Just grow up and communicate

All or nothing.

Very mature.