Joking about Long Island is no laughing matter, Sen. Charles Schumer (D-N.Y.) warned his colleague Sen. John McCain (R-Ariz.) on Wednesday.

Schumer tweeted Wednesday evening: "NYers can take a joke. But if @SenJohnMcCain wants to mock parts of America, stick to Arizona."

McCain apologized Wednesday on the Senate floor for previously joking during a Senate debate that Long Island is "regrettably" a part of the United States.

“In an exchange I had on the floor I mentioned the wonderful people of wonderful Long Island, I made a joke, I am sorry that there is at least one of my colleagues that can’t take a joke,” McCain said. “So I apologize if I offended him and I hope that at least some day he will have a sense of humor.”  

McCain did not name names, but Schumer had tweeted McCain a quick retort: "All of America saw how heroic Long Islanders were on 9/11. #LongIsland deserves an apology."