The former contestants, who finished in third place last season, turned the stage into a slumber party as they performed their new single, "Me & My Girls." Similar to the music video for the song, which is featured on their EP Better Together, the girls, decked out in 5H onesie pajamas, gave an energetic rendition as they tossed their hair, booty-popped and belted out the lyrics.
"We get Britney, Demi, One Direction, Bieber on it," the girls sang as judge and upcoming tourmate Demi Lovato looked on with a smile.
As the song, which the girls co-wrote, reached its bridge, 5H took off the onesies to reveal looks ready for a night out.
The girl group, which includes Ally Brooke, Normani Kordei, Lauren Jauregui, Camila Cabello and Dinah Jane Hansen, continued to show off their dance moves and work the crowd, even making their way down to the judges' table to show former mentor Simon Cowell some love.
Fifth Harmony aren't slowing down anytime soon. The girls, along with Little Mix and Cher Lloyd, are gearing up to hit the road on Lovato's upcoming Neon Lights Tour, which kicks off February 9 in Vancouver. On the tour they'll be performing the six songs from Better Together to all their Harmonizers.
"Each song on the EP has a different kind of vibe to it, but I think the overall thing is just to be yourself and to be OK with what you're feeling," Lauren said recently during "Live From MTV." "So if you're having a good day and want to go out with your girl and see a guy or whatever, 'Don't Wanna Dance Alone' and 'Me & My Girls.' And then if you're having one of those days where you're in a relationship and it's hard, we have 'Who Are You.' So it's a teenage-girl little diary."