Of course we are brothers .. baray ya chotay .. but since we are all members here ... it is best to use courtesy wherever possible
Okay I can call you Istafa as you want me to ... no issues
I have been following this "Bhai" protocol ever since I came here .. I have been addressed as "dude" and "yaar" by friends who are even younger than my kids .. So, you see, addressing others as Bhai establishes a respectful relationship.
I hope you will call me Bhai, instead of Sir ...
I prefer to stay 25 wherever possible