look up any word, like porb:
 
2.
a nickname of someone who maturbates alot.
p1> omg. ryan was so jacking off in math class!
p2> woo! go mustard fingers!

p1>hey mustard fingers! what'd you do yesterday?
p2>masturbate! what else, nigga!?
by fetusraper April 20, 2008
 
1.
When a person goes to itch the inside of there ass cheeks not knowing that they previously did not wiped good enough. When they pull there finger back out and look at it, it has a light brownish tint covering it from sweat and feces that resembles mustard.
Dude my asshole was itching bad. I should have done a safety swipe before i scratched it because I ended up with mustard finger.
by Cangri518 September 05, 2011