flip someone off and flip someone out; flip someone the bird
Sl. to give someone the finger, that is raise the middle finger, a rude sign. (The digitus impudicus.) The youth flipped the police officer off. Not a good idea. He flipped off the cop. You better not flip a cop out! The little kid flipped the cop the bird and didn't even know what it meant.http://idioms.thefreedictionary.com/flip+off
É o sinal rude de dar dedo para alguém.(fazer o sinal com o dedo do meio da mão).