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Hell hath no fury like a Cheerio scorned.

Though a source tells the new Us Weekly Glee costars Mark Salling, 28, and Naya Rivera, 23, were never an exclusive couple, Salling’s dates with other women this summer caused an infuriated Rivera to egg and key his pricey car.

Rivera “went crazy when she read about other girls,” a source tells Us Weekly. “When Naya found out, she and some pals trashed his Lexus."

Still, Salling’s friend, singer Samantha Marq, defends his behavior.

“He’s on top of the world right now and living it up,” she tells Us. “Besides, it’s hard to call it infidelity when they weren’t officially together!”

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Rivera’s rep didn’t return requests for comment.