Here's how I see how the word "Brehs" has evolved.
Brothers > Bros > Brahs > Bruhs > Brehs
It seems logical that the next stage of this word is going to be "Brihs" As an added bonus, we can slangify sisters into sihs for rhyming congruity.
So what do you say my Bore brihs and sihs? Are we ready to embark into this new era of vocabulary?