fix yo' face 

someone advising you to stop looking at them in an awkward manner

you need to fix yo' face

fix yo' face by Stef G. September 17, 2003

fix yo face 

Response immediately given to one who is mean muggin you or if you receive a mean ass look.
Also used in retort to an ugly face, demeanor, or appearence.

"Yo bitch! You best fix yo face! Or I'll be fixin it for you!"

fix yo face by S.E. Girls March 26, 2008