sbfy 

"suck back fi yuh" - popular Jamaican comeback for the insult "SYM - which means, suck yuh mada" (suck your mother)

GUY: yo, guh suck yuh mada
GUY in response: Guh suck back fi yuh (sbfy) mada wasteman!

sbfy by #00fg045 May 9, 2018

SBFY@

Stands for "so bad for you" with the @ further representing the idea that "you" are so bad. Can be used as an insult.

CONG: "I will get a 2.0 GPA this term."
LARROW: "SBFY@"

SBFY@ by Kevin the Cardboard Box March 16, 2021