"aye Monica dumped me cuz i wasn't paying attention to her cuz I was playing ps4"
"yeah man, BBB"
Big Booty Bitches.
You can say it when you see a chick with a big ass. She will never know what you said.
The full meaning on that abbreviation is "Big Black Bruh". It got popular after Dankus Memecus said it several times during his streams on HoI4. Actually, there is a point of view, that he was just stammering with the first "b"-letter, which created an effect of "b-b-bruh" that then transformed into BBB
*your teammates losing 8 tanks in one encirclement*
you: bbb