When you are twerking dat ass, feeling really cute and then all the sudden you let a raging fart fly as your cheeky cheeks are still clappin.
See also SHWERKING
SHWERKING is basically the same as fwerking except in this instance, the fart was accidentally a bit of a shit **also known as shart** so it's when you shart while twerking. If this hasn't happened to you yet, it will.
Omg did you see Alyssa over there fwerking all over the dance floor, she smells like rotten broccoli.