When did you start having an "adult" relationship with your sibling(s)?

I have a brother who is 9 years older than me. I remember when he called me crying over a relationship breakup. He told me all of the details and cried and cried and asked me for advice. When we hung up the phone, I was beaming happy. My brother had called me crying for advice. This was the moment that my brother treated me like a fellow adult.

Did you have a certain point in your relationship with your sibling(s) where you felt treated like an adult? Felt respected? The teasing ended? Your sibling relied on you/you relied on your sibling?

What was it?