Jones: FBS! dude, i got that Fat Boy Swag
Jones: dude help me out of this jacket im stuck (starts to sweat and is struggling to breathe)
Glenn: haha "FBS" (Fat Boy Struggle)
Jones: Thanks man! (sarcasm)
This term originates back to the summer of 2007. Originally an involuntary spasm when touched by a disapproving female, it has since been adopted by others as a formal way to communicate "that's really gross", or "that's fucked up."
It can be used by males and females and should not be overused. If a person is incapable of shaking the entire body in disgust, they are not allowed to say "aww, fbs", and are excluded from the fan club.
Jon: Yeah but he's having an fbs, he's clearly not interested
Jen: What a relief! I'm glad fbs exist!
NOTE: The above example is based on an extremely true story. I swear.