The 'Oops I Did It Again' singer looked head over heels as she laughed and joked with Charlie at the MGM Grand in Las Vegas on Sunday, 17 May.
Britney and Hollywood producer Charlie began dating last year, with Brit recently saying her children adore hanging out with him: "They relate to him really well and they have fun together. He's refreshing to be around and really light-hearted."
No doubt Charlie was on his feet and cheering like crazy during Britney's performance last night.
The starlet took to the stage with collaborator Iggy Azalea to perform 'Pretty Girls', marking Britney's first performance at an awards ceremony in four years.
Britney currently splits her time between LA and Vegas, where her 'Piece Of Me' show takes place at the Planet Hollywood Resort and Casino. It's rumoured talks are currently happening to renew the show for the next two years.