Nicole Richie got the VIP treatment on Tuesday night when she was brought onstage during Britney Spears Las Vegas show, and she unleashed her inner fangirl when she held up a concert tee and freaked out in front of the pop star.

Richie also crawled around on the stage while Spears walked her on a leash, and she got to hang with the singer after the show as well. "Can we all give a round of applause to @NicoleRichie for playing along in the show tonight?" Spears tweeted this morning. "U looked hot crawling on all fours." Richie later tweeted, "Am I alive?"

What happens in Vegas sometimes ends up on Instagram ... but we're glad the ladies shared these snapshots!