Normally mild-mannered singer Taylor Swift was caught on camera during MTV's Video Music Awards Sunday doing something out of character. The "Red" singer, who walked away with the Moonman for "Best Female Video," was spotted uttering a curse word to her friend, fellow star Selena Gomez.

Multiple reports following the incident, in which the 23-year-old country singer can be seen mouthing the phrase "Shut the f--k up," claim the slur was directed toward Swift's ex boyfriend, One Direction singer Harry Styles. Following the band's on-stage introduction for the category for "Best Pop Video," Swift can be seen in the audience mouthing the curse- laden sentence to Gomez. Swift has remained mum regarding the incident on Twitter, but Gomez, who walked away with the win for the single "Come & Get It," thanked her fans online, calling the award a "complete shock."

Swift, who dated the British native briefly in late 2012, was previously accused of publicly insulting him during the Grammy Awards in February. The singer, who opened the affair, reportedly put on a British accent during her performance of the single "We Are Never Ever Getting Back Together" following their split.

The Kentucky native has previously denied using curse-words in her day-to-day life, writing on her official website in a 2012 blog entry "Why Don't You Ever Curse" that she chooses not to use profanity in an effort to appeal to her impressionable fans. "I'm not prejudiced toward people who do, and I have said some things before, but now. … I just don't," said Swift. "It's not some sort of anti-profanity movement, it's not like a way of life or anything. I simply choose to use other words. I like to broaden my vocabulary so that I may improve my knowledge and present myself as an intelligent, respectable young woman."