Pronounced to rhyme with the ever-so popular "uh-oh", a Bro-Oh is an awful Bro mistake.
The mistake: you tried to be a Bro by raw-dogging a ho, but you fucked up and made made that baby, yo!
Dude, I made a Bro-Oh, can you loan me some bills for an abortion?
Shit, I made a Bro-Oh, and now she wants to keep it and get married...