SIL - nephews birthday party

[lollipoplips]

I don't know if I'm being overly sensitive or if this is a really shitty thing to do so interested to hear what people think.

I have 2 sons 18m and 3.
SIL has 2 sons 3 and 5.

It's my nephews 4th birthday next week and my mum gave me an invitation today for his party with just my youngest name on. I assumed it was a mistake and text SIL saying invite only says DS2 is that a mistake. She replied and said no, her son chose who he wanted to attend and he only said DS2, I replied and said I felt that was unfair to exclude 1 nephew from the party and she said she didn't think it would matter as he's never interested in playing with them.

For background my DS1 is suspected Autistic, he struggles socially and doesn't often interact with kids his age, but he loves going to see his cousins, he likes watching them play even if he doesn't get involved. There's no issues between them, no fighting/arguing he just keeps his distance, doing his own thing or watches everyone else. He's a happy boy, rarely has tantrums or meltdowns in public.

The party is at their house, in the garden, they have lots of space so numbers isn't an issue.

I don't know if it's just me being overly sensitive and heartbroken for my beautiful boy as I feel this is the start of how he will be treated growing up.

I'm thinking of just not bothering at all.

Hardly surprised he's how you describe him, obviously his mothers son.

I'm not particularly shocked about those other subtle signs tbh. Being nasty is a personality trait very few manage to turn on/off on demand. Still, no harm done yet to your DC. They're very young and will likely not have picked up on it (though you did) and at least now you know where you stand with them - better now than when your kids are older and more aware, right?
OP, I think both your DC are going to be just fine in the future. You come across as a very loving yet grounded DM. You will all be fine!
Don't dwell on this party or these people anymore! Be done with it or your head will go into a spin. You have to protect your MH. Your SIL and your brother aren't worthy of your time or attention.

Also - your brother sounds useless. I would be furious if my partner did this.

I was wondering if you had heard anything from your SIL about not attending the party? I hope she is ashamed of herself.

I'm generally happy with children being allowed to invite who they want to parties

At 5 I think the parents should heavily be policing who gets invited especially as kids that age can be very fickle and have a friend they declare as a best friend after a day etc.

OP YANBU, your sil sounds batshit. I'd be furious at this and take deep offense.

Also - your brother sounds useless. I would be furious if my partner did this

This,unless there is a back story then that would totally change how I viewed a sibling and it would have a very bad effect on the relationship.