I get it but here he's not the older one (I assume cause of the uniform?)
And about the brother thing I only have to say it's not the same to worry for your siblings, cause you'll ALWAYS do, than to feel in the right to interfere in their life or decisions
But I think it's in part because of parents when older brothers/sisters feel like that
I'm sorry to say it but your sibling doesn't need to prove anything to you but you need to learn to let go and to let them try and experiment life, the same way you did when you were their age.
If not, you will just be seen as controlling and meddlesome... And I'm pretty sure this is not what you wish for.
As the older sibling I too tend to get worried about what my younger sibling do and is often opposed to what she wants, but the worry is still there for me. I applaud the mom, but I just can't instantly accept that decision, u need to prove that you can do it first, I want to become a safety net not something to restrain,
She hates me tho, that's fine, I guess she can't understand me, and I too can't understand her.
Easy to say talk to each other and be understanding of each other when one is boiling hot.
Not me ranting on a chapter of my life at a comment post of a BL manga. This just hit me harder than I thought.