The 35-year-old singer performed the Bonnie Raitt hit at her Piece of Me Las Vegas residency show Saturday after defending herself in June from her detractors.
"So I've been doing a lot of thinking lately, right?" Spears told the audience, according to People.
"I was like, you know what, the press and the media my whole life ... you know, it's really crazy, one minute they tear you down and they're really horrible, and the next minute you're on top of the world, you know?"
"I've never really spoke about it, you know, and I'm a Southern girl. I'm from Louisiana," she continued. "I'm from the South and I like to keep it real, so I want to just make sure I keep having you [expletive] something to talk about, okay?"
Spears confessed in an interview with an Israeli television show in late June that lip-syncing accusations "really" bother her because of how hard she works during her live shows.
"It's really funny -- a lot of people think that I don't do live. I usually, because I'm dancing so much, I do have a little bit of playback," the star explained. "There's a mixture of my voice and the playback.
"It really [expletive] me off because I'm busting my [expletive] out there and singing at the same time, and nobody ever really gives me credit for it," she said.
Spears concluded her Britney: Live in Concert world tour July 3 in Tel Aviv.
She will continue to perform at her Piece of Me residency show at The Axis at Planet Hollywood through December.
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