AceShowbiz - Singer Katy Perry was left red-faced at the Oscars - after her boyfriend Russell Brand chastised her for swearing on live TV. The "I Kissed a Girl" hitmaker blurted out an expletive on the red carpet as she left the Academy Awards ceremony in Los Angeles on Sunday night, March 7.

But she was unaware the late-night interview for British show "GMTV" was being broadcast live in the U.K. at 7.45 A.M. local time. The couple was talking to a "GMTV" 's journalist when Brand was asked about his favorite moment of the evening and jokingly claimed he had seen dwarfs attending the event.

A giggling Perry replied, "I call him on his bulls**t" - and Brand appeared shocked by Perry's remark, telling her, "Don't swear. It's morning in England." Perry had earlier told followers of her Twitter blog that she was enjoying the hospitality at the Oscars, writing "I'm drunk! .. And it's only pre show!"

And she appeared to be feeling embarrassed following her four-letter blunder - after the slip, she tweeted, "Hi 2010, teleporting would be a nice invention now."