I know I was really rude but - can anyone understand where I was coming from?

@iwasrude After five or six times where I smiled and said yes, wow, yes, getting really strong, I snapped and said YES OK WE KNOW.

Why was this rude?? It was a normal response

I don't know what's wrong with some people on MN - they don't seem to live in the real world. They seem to live in some parallel universe where everyone doesn't have real emotions and is permanently #bekind whatever other people do and whatever impact it has on others

Yes, we should be kind but that doesn't mean we should let other people take the piss

Some of these behaviours (not reading the room, always saying the wrong thing, talking about himself/what interests him, not hearing your tone of voice) sound like neurodivergent traits. If I were you, I'd Google and research how to communicate with someone with ASD traits, I think if you learn to communicate with him in a more direct way it'll help.
My SiL is undiagnosed but has strong asd traits. She'll say things like "ill come at 3pm to see as much of you as possible this weekend" and instead of hints like "that would be lovely but we will still be at school activities" (to which she would say "no problem I'll just let myself in" where a neurotypical person reads that they're not welcome) I now say "sorry that won't work for us, please arrive between 9am and 11am Saturday and then I suggest you head home about 2pm Sunday so we have time to prepare for monday". She appreciates the clear instruction, whilst it feels rude to say it, she doesn't understand softer hints/polite ways of saying things like "oh gosh is that the time, you must have things to get on with" (to which she'd say "no it's fine"). I always set a strict schedule and she likes to know exactly what's expected of her.
I suspect your brother thought your littlest walking was amazing (which is sweet) and totally failed to read your tone or body language and simply heard your literal words. Then felt randomly attacked when you snapped. That's not your fault, I get it is very irritating, but maybe research ways to communicate more effectively and you might both feel happier. He is also your sibling, don't beat yourself up, I often snip at my sibling, it's family isn't it!

@FictionalCharacter and @loropianalover are right on the money here. It's not just annoying, it's nasty behaviour.

The rest of his behaviour just seems tedious and irritating. I wouldn't be giving it any energy. I know it's hard to ignore but perhaps with less attention being given to his behaviour he will calm down? Or is that maybe wishful thinking? For what it's worth I have a close relative who is socially awkward (in a different way to this) and can be rude and hurtful . I just do the grey rock thing with him. I know he can't help it, he is suspected of being neurodivergent himself so I choose to shut it out and not accommodate or notice it.

I think he would be better off without you in his life, you don't sound like a very nice sibling do you.

Honestly, you sent the wrong message by smiling at him and nodding along each time he said it. You should have just said “sorry Brother, give me 5 minutes, I need to deal with Julie”

maybe an unpopular opinion - but I think it’s important people have to deal with the consequences of their social disfunction - it’s how they learn…

if he’s been extremely annoying like this I don’t think snapping at him is very out of line.

why do you continue to go out to eat with him if he is rude to waiters? A natural consequence for me would be ‘I find the way you speak to restaurant staff unpleasant and uncomfortable and I don’t want to go with you’

I don’t think anyone is well served by people tolerating poor behaviour from them.

Yeah, you're not responsible for his behaviour but you're telling us it annoys you. You weren't responsible for him standing up and shouting "Wow, look" either but it annoyed you so much that you snapped at him. When he is rude to others when he is with you, if you don't do anything about it then you are participating in that behaviour. Whether you think you are or not, you are condoning his rudeness to others. Your kids will pick up on that, and they will copy him, because you have shown you don't mind it (by your lack of response). I'm not most people's mother, but I still try and shape society into one that I'm comfortable with being in. This means using my words instead of pretending that it's not my problem.
In regards to your OP, I don't think you were rude. He was apparently excited about his niece but equally could've been making it about him. Either way, it wasn't a good time or you and he didn't help.
I feel as though you won't like my response, as while I'm agreeing you were NTA, you don't want to try and make your relationship with your brother any better.

Would you have rather he ignored the fact his niece was doing something just because you were busy with the eldest?

What does he say to shop staff and waiters? Is he shouting at them or pointing out things that are wrong? Because in your OP you say he's ranting at them but then you say he's whinging at them. There's a massive difference between ranting and whinging.

Oh I hate when people are like LOOK LOOK at something. Don't blame ya OP

OK.. I don’t see your circumstance changing much then unfortunately. It’s no way to live, you were not rude for snapping at him, just at the end of your rope while already trying to deal with 2 kids. I can see you don’t want to be rude/confrontational towards him so spending less time together seems to be the way forward.

It’s hard to understand why you have no issues being snippy with posters here, but cannot pull up your sibling on rude behaviour. You say you won’t do it because you’re not his mum, what’s the point of this thread then?

I am completely on your side in that you were not being rude, and he sounds like a complete pain who wound you up with silly behaviour. But there are obviously some other family dynamics at play where you feel you can’t say anything to him. Unless we know what those are or the reasons behind them, we’re not going to be able to be much help.

He is rude and deserves a bit of rudeness/honesty back. If you’re not going to be the one to do it I suggest spending less time with him, because it’s only making both of you miserable.

I don't get why you didn't say 'brother I am concentrating in oldest now knock it off'

I think there can be a bit of a grey area with being rude and being blunt. If he needs very blunt communication then it might not come across as rude from his perspective. It might be that he even prefers to be told something bluntly but clearly rather than hoping he'll pick up on a hint.

Either he's neurodiverse / lacking awareness/ understanding, or just doesn't care that he's being rude.

If the former, the solution is to reply calmly and straightforwardly.

"After five or six times where I smiled and said yes, wow, yes, getting really strong..."

This is totally the wrong reply to someone lacking awareness, because you're pretending to enjoy the conversation - no wonder they would be confused and hurt when you suddenly snapped. I'd say, "Sorry bro I can't talk right now, give me 5 mins please".

This isn't rude, and will generally be appreciated by someone neurodiverse. If he's not neurodiverse and just doesn't care, then this approach does no harm anyway - and you'll start to find out which one it is.

What you said was necessary.

This MAY be irrelevant here but personally I am std of "male entitlement". As I said this may not be relevant here but every time a man or boy says something to me other than "Hi Sian", I fear the worst. And 90% of the time I hear the worst !!

Yes. But unfortunately you picked the wrong behaviour to target. You need to speak up when your brother is ranting at shop staff (or refuse to go out with him) rather than letting it build up and come out over something well intentioned. All your brother will now see is that you snapped at him when his was showing admiration for your child. So in his mind, you're snappy and unreasonable. You need to start being more assertive with his bad behaviour or create distance from him.

There’s no one who can piss you off like a sibling.

In the circumstances I think this is insignificant. I would have snapped too - can't bear people endlessly repeating things, especially if it's done loudly.

Sorry OP but let him get hurt! Jesus he’s a grown man, I’m sure he can take it.

He can happily dish it out to poor wait staff but gets his feelings hurt if someone tells him to behave?

I’d be setting him straight as a sibling before he comes across the wrong person in life who won’t treat him so kindly.

He sounds insufferable. Shouting at waiters and shop staff is dreadful- it’s bullying- and I couldn’t go to those places with someone who does that.

If he can’t read the room you need to just be blunt with him. Take the emotion out.

‘You need to stop being so loud.’
‘We won’t be coming out for dinner as you’re always rude to wait staff.’
‘You need to go home now.’

Does the family usually skirt around him and pander to him?