To be a person who is in a "bruh" state but not quite there.
Friend, "I just lost a game of CS:GO, my teammates are fucking 'amazing'"
You, "Brub/Bruhb/Brrrrr.../Bruhhhhhhb."
like a bruh moment, but worse
girl: i accidentally leaked nudes to my dad
guy: bruhb thats a fat rip
bruh with an extra b to really emphasize the stupidity of the person you are using this word against
person - "is grass green or red?"
person - "Bruhb..."