AIBU, am I stopping to their level?

[TwoYearsMarried]

My sibling and I haven't spoken since November. He is known for acting like a petulant teenager and is quite over the top with his reactions. The smallest of things will make him not speak to people for weeks. He's very childish for his age (31).
Anyway his son, my nephew, and my DS do heaps together. Spend 2 days a week together at Granny's house and they are close, as close as you can be anyway at 3 years old.
It's my DS birthday this weekend and we're having an outdoor garden party. It has been rearranged from a date a few weeks ago to allow for it to be held within Covid restrictions.
Because my brother doesn't speak to us, my SIL has also decided to not bother.
If we text it is factual only.

So I text SIL to invite them to the gathering for the initial date. She replied saying she'd check with my brother. No response. I had to chase. No response to the chaser. In the meantime we postponed the date, I text to let them know the new date. Again no response.

Mum (who thinks the sun shines out of their backside) comes over this weekend to say my brother won't come because he wants to watch a football match. I find that insulting given that we travelled 50 mins with a toddler and (at that stage) a 4 month old baby to see their son on the day of his birthday. They didn't visit to see my DS on his actual day of birthday and they again haven't

Think a regular response on here was 'it is an invitation, not a summons'. You've invited, they've said no.

I don;t think it is insulting, but I think you should not make these people a big priority in your life. So if they invote you to something - say yes if you want to go, and feel no remorse saying no if you don't.

Focus on the birthday party, that is what really matters.

...acknowledged the invitation to the rearranged date of the party.

I've bitten the bullet and text them to tell them they don't need to come this weekend (effectively uninviting them). My parents wholly disagree and think it's cruel on their son but why should I have the agony of my brother making pathetic excuses and my SIL feeling like she's being dragged to the party. I'd much rather them not come at all.
Many of the wider family will be there and will probably ask where they are and I have no issue explaining the situation.
Do I look unreasonable? Wwyd?

...and should read "stooped" to their level. Sorry also pressed send too quickly. Can you tell I'm writing in fury ;)

@colouringcrayons sorry I pressed send too soon. I've effectively uninvited them now. See later post x

Why isn’t he speaking to you? It’s disappointing they don’t want to come but if he has plans that’s up to him, and maybe as you clearly don’t get on he doesn’t want to spend time together?

Yes that’s harsh, but I wouldn’t want to spend time with someone I wasn’t speaking to either, sounds stressful

[quote TwoYearsMarried]@colouringcrayons sorry I pressed send too soon. I've effectively uninvited them now. See later post x [/quote]
But they were already not coming? What’s there to say to other people except they already had plans so couldn’t come?

Its sad that the cousins can’t see each other but not the end of the world. The dcs will pick up on the hostility between you and your db. Just leave it, they dont have to do anything

I would have left the ball in their court and not uninvited them.. they have not said directly to you that they are not coming.

Sorry should have said that my brother was digging his heels in and going to watch the football first (yes "plans" maybe, but not something he should really miss his niece's birthday for imo). And so my SIL was apparently going to come with their son to the party, but she hadn't bothered to reply to tell me that directly and it came via mum. It's painfully obvious they didn't want to come so I'd rather just not have them there.

Many of the wider family will be there and will probably ask where they are and I have no issue explaining the situation.
Do I look unreasonable? Wwyd?

What are you planning to say about the situation except they couldn’t make it? Sounds like you’re just trying to make this more of a drama tbh, are you sure it’s just your brother who has a tendency to be over the top with his reactions?

But you changed the date, he now has plans and can’t make it, you’re being over the top tbh. It’s a child’s birthday party, it’s not the end of the world if he’s not there

I couldn't get this worked up about a child's party myself, the day will be lovely and plenty of fuss will be made of the child.

I think you're putting a lot of pressure on this cousin relationship. I barely knew my cousins, it hasn;t felt like a big loss in my life.

You are being really over the top about it. Just accept that they aren't coming and make the effort with them that you are comfortable with.
It seems to me you are creating a load of drama that really doesn't need to be there.