Splash NewsSometimes you just get caught up in the moment!
And if you're Britney Spears, that moment gets captured on video for millions of people to see.
The pop princess was performing onstage last night at her Las Vegas residency dubbed "Piece of Me" when a concertgoer taped her missing her cue.
Now, before we go into details about what happened…let us just say one thing: Leave Britney alone!
Okay, glad we cleared that up. Brit Brit performed "Alien" to the sold-out crowd and seemingly missed the mark on when she was supposed to sing...though her voice still seemed to be singing the song. It looks like the mother of two got so excited and distracted by all of her fans, but immediately picked up her mic and carried on like a true professional.
Britney had a special, very famous guest last night at her Sin City concert as well.
Nicole Richie made a surprise appearance and was brought on stage by her backup dancers during her hit song "Freak Show."
After joining the pop idol on stage, the former Simple Life star was given a T-shirt with Spears' image on it.
Spears, who recently went brunette, praised Richie on Twitter. "Can we all give a round of applause to @NicoleRichie for playing along in the show tonight? U looked hot crawling on all fours," she wrote.
The 32-year-old "Perfume" singer then tweeted Richie directly, writing, "Thanks for dancing tonight!"