Sarah: Your so stupid looking in those uggs, yoga pants, crop top, and choker.
Hannah: Cash me ousside howbow dah
Sarah: Ok let's go! I just got my stiletto nails sharpened.
This was the phrase an angst teen said on the Dr. Phil show. Her accent made it sound different, but she said "Catch me outside, how 'bout dat?" (meaning: "you so tough, lets take this outside to fight"). But since it "sounded like "Cash", that has taken off on the internet.