Honesty that is maintained between two bros that must not be broken. Bronesty is stronger than honesty. It is swearing on the bro code to swear to tell the truth, the whole truth and nothing but the truth, even if it means having to admit that you're gay.
Tim: In all bronesty, why did you get a broner when you were just looking at me?
Boris: Bronestly, I think I'm gay.
A mere phrase that defines something that is almost indescribable in English words. It is beyond brohood or broship. It is a brosphere. An undying, indestructible, omnipotent bond between bros that is incomprehensible to outsiders and lasts beyond biological death.
Tim: It's bros or bust.
Mark: To death and beyond, bro.