Do older brothers have more responsibility?

[Kardelen]

My husband has 3 other siblings but he’s the eldest. The age gap isn’t massive between them either.

the third one just got married, and he’s eating himself up saying how he should’ve stepped up as the older brother and showed some guidance, asked questions or showed more interest. ( even supported more financially, we already did Give about 500-550 between us but he thinks he should have given more). Husband earns slightly less than the brother that got married.

I am also on mat leave with two young kids.

so, am I being unreasonable to think that if he is getting married and doesn’t come to ask for info for how things are done, we should assume he knows it? Or should we have kept asking questions if he is okay, if he needs help, if he doesn’t know what he’s doing?

Not to do with being older, but if one person in the sibling group (or friendship group) has done something that the other is about to do, isn't it normal conversation to reflect on what you were really pleased you did / wished you had done / wished you hadn't done ?
As it happens, our youngest sibling got married first, and it was useful to hear their experiences, before my wedding. Same as whoever has the first child in the group, or whoever buys a house first and so forth.
When most people do "big" things in life, they tend to chat with other people who have done the same things in recent years.

My younger brother and I often do turn to our older brother for advice. He's definitely the "head" of the family. Most of the time, it's because he's done something significant before we have, so he's the right person the ask. The rest of the time, it's because we look up to him (despite being in our 30s) and value his advice and knowledge.

Doesn’t know what he’s doing in what respect? Doesn’t know how to get married?? You gave them £550 towards the wedding? That’s already above and beyond imo, not usual for siblings in my experience.

@UsingChangeofName thank you for yo ur reply.
but would you expect the brother that has done it to come to you to tell you, or would you ask first?

and he’s eating himself up saying how he should’ve stepped up as the older brother and showed some guidance, asked questions or showed more interest.

Surely that's just being a decent sibling and nothing to do with being an older brother necessarily?

@PassMeTheCookies would you have asked your brother or expect hIm to tell you without asking?
In a normal day they also don’t look up to him they mostly disrespect him by laughing at certain things he does

Did their father die or leave the family young? I don't think it's unusual for an elder brother to feel responsibility to step into the "head of the family" role, even though they may not really know what that looks like if they lost it young.

I don't think an older sibling should feel responsible for younger ones at all.

If they want to advise and contribute to something like a wedding then that's nice provided that the younger one is happy with it and it isn't done in a manner which treads on toes and interferes. There should be no obligation though.

It would just come up in conversation.

B2 "Jane and I have got engaged"
B1 "Oh, that's lovely. Congratulations"

B1 <Cracks open a bottle, or gets round in>

B1 "So, tell me more - made any plans yet ? Where, when, How, sort of thing ?"

Then B2 might say - "not got round to that yet, not for 18months, 2 years" in which case B1 asks a couple of months down the line

Or B2 might say - "we were thinking quite traditional - much like you did" at which point B1 says. "Oh, lovely. We had a smashing day. You know, the only thing I'd do differently is X. Let us know if you want to have a chat about it. You can come round for a takeaway in a couple of weeks. Let's be honest Kardelen has a better memory for detail than me, I bet she'd love to be involved if you want any help or to hear what we discovered"

You seem a bit fixated on who should have said what to whom, whereas IME these conversations just come up when you are chatting. There's no etiquette about it. It needn't even be your brother. It could be a friend who got married recently. You just want to talk things over with people who have experienced the same event recently so might have some top tips.