Feuces =Fucking Deuces.
Fuck you and I'm Deucin out.
Usually done by sport bikers when passing someone illegally, bike lane, turn lane, splitting lanes etc.
When more than "Chris Brown's" deuces is needed.
For example, you see a bunch of grenades show up. One would throw up the Feuces
Girl: Please give me another chance, I promise I won't ever cheat on you again.
Guy: Hmm let me think about that. No, Feuces. ,\/,
When you honestly don't give a fuck and you are leaving a party or event. You throw up the Feuces.
To execute the sign with one's fingers, first start out by throwing up the middle finger and let that ring finger follow, extend the thumb and you have done the Feuces.